And why is that exactly?
because virtually nothing can ko it, it's free to set up a dd and maybe another dd, thanks to multiscale. With genesect goen thats one less revenge kill that will trouble it. Not to mention ouside of it's best set DD it can preform well with weather specific sets, mixed sets bulky offensive cb sets. Thanks to his great sats movepool and multiscale nite can fit in on any team with a little support.
my god what a lot of beep, dragonite dose not need fire punch if he is on rain he learns waterfall and aqua tail too if your going down the dd route and there is earthquake.
he also cna make use of thunder and hurricane in the rain too on his rain mixed set.
Your argument is invalid ; Haxorus is the best Although I'm thinking of replacing it with Salamence , atleast it can survive an Ice Beam from Politoed and r0pe it with +1 Outrage.