Yep.
My immediate thought is that it works because of who's popular bot right now as ADCs. Jinx, Ashe...any ADC without a dash/blink escape could get caught out bad. Sivir is particularly fucked since the strength of her spellshield is negated and her low AA range might make it easier for her to get caught by pillar.
His passive sustains him well enough, he's not a particularly mana hungry, though to be honest I never max'ed E first ever on him so I don't know if that holds true in support. His ultimate is definitely nice for his ADC. His damage reducing on Q is nice for bot lane trades assuming he can get to the opposing carry. Wards well, safe roamer, strong aura carrier, basically lots of the stuff that makes him a good jungler applies in support...
...but to the point that he currently has the highest support win rate in the game? Goddam it, what?