Why is this Pokemon so good? I'll tell you. "If Ice Beam can freeze, it will."
In all seriousness, this guy's one of the most underrated mons in the metagame. Think of an Abra that can set up and take hits and Recover. Used in conjunction with Larvesta is pretty annoying to pump Mienfoo out of the way (I don't care what set you run, Mienfoo's not going to use Stone Edge against a +1 Porygon). I've also seen it used with Exeggcute and, as you mentioned, Toxic Spikes.
All I can say is thank you GK!
Don't count the days, make the days count.
Katakiri: How did you even get into this university?