it's not only about how low end PC's could run WoW so well, just look how smooth WoW felt with those animations, combat, just everything, those animations and optimization is the reason why ppl rather play WoW, even these days, lots of if not every MMO is nowhere near those WoW smooth standards! Devs should realize that nice and fast animations and optimizaton is more than half way to success , you don't need to trust me but that's just it.
let's take MOBA's - LoL, Dota or SMITE - all those games are so smooth, look at those animations in LoL and Dota, so quick, responsive, no wonder those games are so successful.
look at CS:GO, Overwatch - boom, again so smooth and silky!
Like who whould like to play unoptimized, clunky, not responsive games? pff..
Even very successful PUBG which seems to be still quite unoptimized does feel well while playing...
and Pantheon? I can already smell how clunky this game will be, I want Pantheon to be great game but it won't happen, it can do just well but it will be nowhere to being successful ...with their engine they won't be probably able to make it smooth and silky!
YES! First, it's all about being SMOOTH and SILKY!