I'm sorry, but this is way wrong. -ates are counterable once you know the set, but dragonite requires 2 checks per team. Skarmory is obliterated by thunder punch, and considering Dnite needs nothing for its last slot, it can run it at little to no cost. Dnite needs 3 moves - DD, Espeed, and Earthquake - To absolutely destroy the metagame. Pixilate and Aerilate sets are both extremely effective and there is virtually no reason not to run them. Multiscale means it is incredibly good at setting up, and with roost it literally does have no counters.
No, its not like megagross in OU. It is WAY more overcentralizing and can obliterate any of its checks with the proper move, period.
Also, there should be a baton pass clause in the metagame, there is one in ubers iirc.
First of all, since this is easier to answer, pertaining to the metagross comment, I meant that it is a top tier offensive threat that will destroy entire teams if unchecked, just as megagross will. I'm not saying megagross is as centralizing, it's just a loose comparison.
Thunderpunch is a shaky answer, as overall it is vastly inferior to a number of things. You lose out on roost, which is really nice to have (though admittedly not necessary), and, as it is only super effective on 2 types, the coverage isn't even that helpful and leaves you much more open to being walled than other sets, it's really pretty weak, to be completely honest. Also, forget all that, I just ran some calcs; against physically defensive venusaurite Skarm, it only has a 32% chance to 2hko Skarm w/ Tpunch, and iron head is a guaranteed 2hko in return (0 Atk, obviously). That is your single most powerful option, and it still loses 68% of the time. Granted, that's not factoring rocks in on either side, so that does change it a bit. If dragonite switches in, takes stealth rock damage, and tanks a relatively weak attack, 20% is actually all it needs to be, then Skarm comes in and ohkos it every time. But wait, it has roost! Nope, it has Tpunch, so it doesn't have room.
Aside from that, anything w/ solid physical bulk that's not already weak to fairy can be stopped by a bunch of aggronite stuff. Gourgeist is a good abuser that 1., initially resists ground and therefore discourages EQ yet is only weak to it after mega evolving and resistant to everything else (bar Tpunch), (honestly though, it's not that great; there are better answers for sure.
Another very good answer that DOES work on offense is altarianite/Pinsirite arcanine. It has access to morning sun for recovery, WoW, and intimidate just to give it that extra bump. It forces Dnite to guess which set it is, as a single misprediction ends your dragonite. And entei is basically the exact same, except it lacks intimidate and morning sun. Latiosite victini (actually a pretty good set) walls it to no end, and basically a lot of fire types in general ruin it's day. But its biggest problem is its lack of versatility. While it is VERY good, it only does one thing, with slight variations. In MaM, you can't always say from the get go what will beat you. Just as gyarados is destroyed by rotom, yet mega gyarados slaughters rotom, type/ability changes can totally screw you over. It's not always apparent what you have to eliminate in order to sweep your opponent. Basically, mix and mega is a game of "who can better lure their opponent and smack them silly." And dragonite cannot do this. Period. In fact, it's very prone to it, due to its lack of options. Yes, it's incredible at what it does. No, it's not easy to surprise and kill. This makes it very easy to play around unless the dragonite user is significantly better.
I'd like to encourage more discussion around
Dragonite
Here's a replay where my Dragonite easily beat Skarmory, how awesome Don is :]
http://replay.pokemonshowdown.com/mixandmega-246046446
I have to get back to work, so I can't watch it, but something tells me that specific set wasn't actually well suited to taking it on. Slowbronite needs almost no investment in its defense to avoid the 2hko from anything, though it's not quite the best set. Venusaurite can almost always beat it, and is better overall.
