Krush is an amazing card. He's just not an amazing hunter card. If he was a neutral legendary, I'm sure you'd see him in a lot of decks, but hunters really have no room for him and he doesn't synergize well with anything they do outside of being a finisher (but who needs that, hunters already have board control and have you at 5 hp by turn 7-8).
Either way I don't see them buffing legendaries anytime soon. Think they want to mainly treat hearthstone like a physical card game, and only nerf in extreme cases. Have they even ever buffed any cards since beta ended? As much as I'd like them to buff Illidan (he fucking deserves to be a 5/7, 6/6, or hell. even a 4/7, still can't believe he's a 7/5 that gets removed by literally everything--he should just be an improved late game violet teacher), it's probably not going to happen.