Ice needs to resist Water and Flying, IMO. And maybe even Grass. It's supposed to be a defensive type, after all. It currently only holds one resistance - itself! That's pathetic.
It also could do with being better during Hail.
Water and Flying is fine with me, but not Grass. Too many things resist Grass as it is. MAYBE it should resist Ground instead, however I'm not sure about that just because of all they Flying types and Levitators.
Anyhoo, I think GameFreak legitimately wants Ice to be the way it is now. Why? Because it oddly makes sense. Freezing temperatures will easily damage and kill things, which is why Ice is strong offensively, but actual physical ice is usually fragile, which is why it's bad defensively.
So as much as I'd like being an Ice type to not suck so much, I don't think that will ever change.
Yeah, fair point on the Grass thing.
At the very least, we could use a couple more speedy Ice types. Or some more interesting dual-types.