I understand that Deoxys-D is definitely a great Pokemon, but some of these arguments are ridiculous. Deoxys-D can't run Taunt / Spikes / Stealth Rock / Magic Coat / Thunderbolt / HP Fire / Psychoboost. There ARE Pokemon that set up on and make life hell for Deoxys-D teams (Double Dance Thundurus-T, anyone?) and it's still possible to spin against these teams. Oh wait, Deoxys-D might have a coverage move that can KO your spinner? Maybe you could switch it out to scout for it. Deoxys-D, once again, cannot have all of those moves at the same time. Is the aggregate of its sets broken, or is Deoxys-D broken in individual cases in games?
No one is arguing that Deoxys-D can run all of these moves, the fact is, it CAN run these moves, and this is what makes Deoxys-D so hard to handle. The fact of the matter is, if Scizor is your Deoxys-D check / counter, and you run into an HP Fire variant, then your counter got raped, AND Deoxys-D is sitting pretty at 100% health, still able to set up SR and Spikes or whatever the hell it wants. This is the scenario Deoxys-S created as well, it had counters and checks, but its wide movepool allowed it to fuck with you 100% if you got its set wrong, and this made it unhealthy for the metagame.
In regards to your spinner switching in and out the same thing applies for Deoxys-D. You can bring in your spinner, take SR damage (and lets say Spikes), and then, expect a T-Bolt and switch right out. However, it turns out this Deoxys lacked that super effective attack you were so worried about so - fuck - that pokemon you switched in took hazard damage for nothing, and Deoxys-D got another free turn to set up yet another layer of Spikes. Now you have to get your spinner back in, take even MORE damage, and hope you are not taking a Night Shade on the switch, or if Deoxys-D simply switches out, free to pressure your entire team (and your spinner) with hazard damage. This is the coinflip scenario Deoxys-D takes.
Yes, entry hazards are excellent and give the Deoxys-D team an advantage, but the tradeoff is they risk losing to Timid Volcarona / Double Dance Thundurus-T / Terrakion being played competently. Deoxys-D is not Deoxys-S. It cannot Taunt everything, no questions asked, and yet it isn't bulky enough to avoid being 2HKOed by strong attackers. What about Deoxys-D and its ability to set up hazards makes this worth it, or even broken? Why are hazards such an insurmountable advantage? At what point does "early game advantage" become enough to ban a Pokemon that is almost never an offensive threat in a match?
Actually, both Volcarona and Terrakion risk being Thunder Waved (Terrakion can Sub but its Sub gets broken by Night Shade so again, its a coinflip, so its not really that easy to set up on Deoxys-D as you claim. Heck, if I got to cripple your Terrakion in exchange for my Deoxys-D's death, thats a fucking win in my book, a 1 for 1 that took out a danagerous set up sweeper that my team no longer needs to worry about. Remember, those hazards that Deoxys-D sets up don't have to be up all game. Your opponent can increase the pressure by using pokemon such as DD Nite (haha you lacked SR up turn #1 cos Deoxys-D cockblocked it) or other set up sweepers that make it next to impossible to get your spinner in safely and spin. Even then, many HO teams carry a Gengar, so you need to predict the Gengar switch in, OHKO it, and even then you get forced out by something faster anyway, racking up the hazard damage. Sure, you might spin eventually, but by the the hazards would have taken their toll, and its too little too late.
These hazards, are such a problem because it is free damage per switch, and an offensive team forces switches like no tomorrow, least you get swept by something. The issue at hand is that Deoxys-D will almost always get up 1 layer, but often 2 layers, exceptionally early in the match, and then it dies, and your opponent can put instant pressure with a high powered sweeper ready to break your team down. The ease and how consistent it is makes Deoxys-D very popular, because despite what you claim, in practise its very difficult to stop Deoxys-D doing its job, as its so good at gaining instant momentum for the HO team.
At what point does "early game advantage" become enough to ban a Pokemon that is almost never an offensive threat in a match?
Highlighting this point again. Don't you dare try and get cute here, you are well aware we banned Deoxys-D which was also never really an offensive threat. Sure it had a LO set which was nice, but what pushed it over the line (based on the opinions of many who banned Deoxys-S) was its DS and Spiker sets, which could get past their counters depending on the moveset choice, and fuck you over, NOT for the offensive presence they had. Deoxys-D does the same, but to a slightly lesser degree than Deoxys-S and this is what is causing frustration for many, since it really is so hard to handle.
EDIT
I think its pretty well established that sr/spikes/taunt is pretty mandatory. So he really has one 'free' slot. If your not using spikes and sr, your better off using something else.
Actually I ran into a HO team that happened to have Rocky Helmet Garchomp with SR (prevent that Starmie from spinning once it hits 25% or below I guess), and the Deoxys-D had Thunder Wave + Spikes + Taunt, which made it exceptionally hard for my lead Sash Terrakion (with taunt!!) to beat since Mental Herb would shut me down as I would get paralysed, and then taunted / hazards got set up.
Also I am in no way saying that Deoxys-D is unbeatable. FFS Genesect was beatable with the right prediction, so was Tornadus-T, and heck, so was Excadrill. However just because something might have a check, or a counter, or something does not mean its not broken. The wide movepool of Deoxys-D, and how flexible its move choices can be make dealing with it exceptionally hard, and if it has the right moveset / item choices, your counter got shut down / killed and you just lost the game, the fact that Deoxys-D has 1-2 moveslots that can literally be anything it fucking wants make it suck a hassle to prepare for. Granted, many pokemon can have a versatile moveset (like MixNite for example), but what pushs Deoxys-D over the edge is its bulk and ease as to how it sets up its hazards, and how it can shutdown many attempts to set up on it. Against Dragonite, you might lose your Balloon Heatran to a surprise Superpower, but then you know its Mixed, and you can deal with it accordingly. Deoxys-D however, just got a surprise KO on Scizor, is at 100% AND has the bulk + speed to still get up a layer or 2. This puts you down 2 layers and a pokemon, giving the HO team a _MASSIVE_ advantage. If you have a counter for Deoxys-D great, it might work once, it might work twice, but maybe the third, forth and fifth times you run into the moveset that cockblocks your counter and lose all 3 times. The fact is Deoxys-D can do this easily, and at no net disadvantage because ALL of its sets are viable, good, and get around certain things that counter it. This isn't like EQ Latios which is rare as fuck, there are so many viable Deoxys-D sets running around with only slight differences from one to the other. All of them can get past their counters / checks and this make sit such a headache.