Why do we never see Ogre Magi in the proscene? Specifically over Crystal Maiden

I can't recall a time I've Ogre Magi drafted, but Crystal Maiden is often picked as a hard support. I'm under the assumption that Ogre is a far better support/hard support, but I'd be willing to hear counter arguments. I hear a lot that she has "unparalleled disables at level 2", so I thought I'd look at that.

She has a 3.5 second slow for 30% movespeed and a 1.5 second "stun" which deal a total of 170 damage.

Ogre Magi has a 4 second slow for 20% movespeed and a 1.5 second stun for for a total of 184 damage (104 of it as a DoT). Also, both spells have a further casting range.

Almost the same amount of disable and damage. Ogre also brings a lot of survivability because of his high Strength gain and base armor. He can also end up dealing considerably more single target damage in a teamfight if he gets a good multicast off. And usually survives long enough to get more than one rotation of his spells off. All of this is not even mentioning his Bloodlust, which I consider one of the more powerful carry buffs in the game.