All Gens Ask a Simple Question, Get a Simple Answer Mark II (RoA edition)

Why is Zapdos so much better in Generation 6 OU than Generation 5 OU? It didn't get a mega evolution, it didn't get any new good moves, and none of its good moves were buffed in Generation 6 (except maybe defog removing sticky web).
 
Why is Zapdos so much better in Generation 6 OU than Generation 5 OU? It didn't get a mega evolution, it didn't get any new good moves, and none of its good moves were buffed in Generation 6 (except maybe defog removing sticky web).
You replied yourself, Defog is the reason Zapdos got better in the first place, plus checking some stuff that are more common in XY, like MPinsir, Talonflame. It's not a bad mon in BW but there are better electric types in general, and it's a bit useless against some playstyles(DragMag), so you would rather have something else that hits harder or does a better defensive role than Zapdos.
 
Why is Zapdos so much better in Generation 6 OU than Generation 5 OU? It didn't get a mega evolution, it didn't get any new good moves, and none of its good moves were buffed in Generation 6 (except maybe defog removing sticky web).
I just remembered that defog doesn't remove stuff on the user's side of the field in Generation 5. That explains everything.