If Dugtrio had shadow tag rather than arena trap, do you really think it would be any better or used any more? Especially since it doesn't want to be in on pokes that are immune to its stab more often than not.
Thing is,with so many new powerful threats,it makes ST look less threatening,but I'm pretty sure it's going to be banned sooner or later :/
All the ST users have the right stats to abuse it,Duggy on the other hand,doesn't have those stats.
So although he doesn't have them,the 3 ST mons do. So instead of comparing them to Dugtrio,let's actually see if they're broken.
Shandera: Can trap and kill a crap ton of mons. Great revenge killer,but it can switch in on almost any Ice,Fire,Steel,Poison(not toxic though),Grass,Bug,Normal,and Fighting move and OHKO the other mon.
The list of mons Shandera can switch onto is huge.
Shandera can also abuse Choiced Fighting/Bug moves(either by Trick or by sheer luck) to set up and sweep your whole team.
Gochi: Bulkier,but weaker Shandera. Gochi is pretty much just as broken,but lacks all of Shandera's set up moves and sheer power,but what Gochi lacks in power,it most certainly makes up for in bulk.
Gochi can trap a lot of things Shandera can't,like Bulky Waters,and just either set up in their faces or outright kill them.
Wobb: We all know Wobb. He can do one of two things to your team. He can either give a set up sweeper one free turn of set up,or he can kill one of your mons.
I see them all as broken.
Switching is a huge part of pokemon,and these mons all prevent that and have the stats to abuse it in some way.
Shandera and Gochi can GUARANTEE one kill per game while Wobb can give you a free turn of Set up.
You can argue that Magnet Pull and Arena Trap are the same,but these mons can trap ANYTHING. It isn't restricted to just Steel types or anything that isn't Flying or doesn't have Levitate/Balloon.
From all my time on PO,people just hate it.
The biggest problem is how the only way to escape is by using and otherwise useless item.
Skarm can use it for Magnezone,but other mons like say Gliscor.
He needs his Toxic Orb or his ability is useless,while Shandera can come in(Preferably not on an EQ >.>) and easily kill with HP Ice.
Your Doryuuzu counter is now dead and you're ready to be swept :/
But all of them have alternatives now,and none of them are broken without it,so it MUST be the ability.
Ban Shadow Tag,not Gochi/Shandy/Wobb.
Back on to Drizzle.....the Drizzle + SS clause seems like it would work,but it might be too complex,and AFAIK,we want simplicity.