Why are so many people playing Blitzcrank?

Last pick in ranked? Can't play support but the four other teammates shoot down your picks and are threatening reports if you don't play "a support champion"?

Well have we got the champion for you, It's Blitzcrank!

Blitzcrank's the one-stop-shop for all the support needs of you non-support players. Proper mechanics? Don't need 'em! If you can land a skill shot, you can play Blitzcrank to a mediocre enough level that when things go south, you can shift responsibility too and join in on blaming the jungler.

Non-support players getting forced to support still want to make plays.

According to http://www.lolking.net/champions/ he currently holds the sixth-highest win rate, and the highest among all the support champions. The reason? It's hard to truly counter him. Leona is a fairly smart choice against him, and what do you know? She has the second-highest win rate among the support champions.

He's my go to support as a non support main, if he's banned then I go thresh, he's just so easy to play, sitting in the bush is an almost sure grab. Not to mention the hitbox on his grab is screwed up been that way for awhile, because of that there are grabs that shouldn't have happened that suddenly do. The "WTF HOW THE F*CK DID HE GRAB ME?" or the "WTF HOW DID I ACTUALLY MAKE THAT GRAB" happen to me at least once every game there is a blitz. He has a grab that also stuns for a split second, a knockup, and a silence that's only a 30 sec cooldown with no CDR. Only champs that I fear as blitz are morgana, sivir, and leona, and don't forget the morgana sivir bot lane, that's just for blitz and thresh.

He was free relatively recently too, which may have caused a fresh wave of people to pick him up (either because they tried him and liked him, or because they had a rough time opposing him and figured he was op).

Personally I don't care for blitz as a support (although to be fair I'm a big leona user) since I find he's worse than useless if he doesn't land grabs (since his ult passive can 'steal' adc farm or otherwise throw off their csing), and avoiding grabs isn't 'that' difficult if you always keep minions between blitz and yourself. Granted lots of people don't seem to be able to avoid blitz's and particularly good blitz's zip into position and grab before theres a chance for the target to reposition, but he just seems less reliable than a lot of other supports.

Easy to snowball with him. 1 good hook can win you the game.

Because low ELO people who don't play support think Janna is a bad pick :^)

Most powerful non-ultimate in the game

His passive agressive nature makes him both a very safe and very powerful pick, even if you are unexperienced as him or the support role in general. He is also designed as a bruiser rather than tank or mage like almost every other support in the game.

And i'll be completely honest, most brusiers actually make for better supports than the "traditional" ones. The reason is that they can still get tanky, they have CC, and generally more mobility and damage than the "traditional" list.