I don't think anyone is disputing the fact that Hibernate is a cool power and situational. Hibernate however offers nothing to the main purpose of the AT, which is to be a tank for other other players. Not to sit there invulnerable while your fellow heroes faceplant all around you.
Even despite the Ice Tank subpar rating compared to other Primaries, I've had a blast playing mine. But now,... well, the numbers speak for themselves. Ice is in need of a buff, not a substantial cut; especially for those ice tanks that haven't taken hasten.