Kuzmenko has played a grand total of round abouts ~15 minutes at even strength with Miller this year and...one single goal was scored.
I don't think you know what you're talking about here.
No, Kuz isn't gonna score at that same rate even though he's the sort of player who is naturally going to have a higher than average SH% by virtue of the way he does all his real work within a 12ft tether to the opponents net. Nobody was realistically expecting that.
But more than that...what the heck does it matter what Kuzmenko would do with "less talented linemates" than Pettersson? The reality is...that's what he's paid to be in Vancouver to do. Support Petey. He does it well. The two read off each other extremely well and Kuz has the finishing touch around the net to really help cash some of those setups that are going to come his way.
That's why they ain't trading him. He's worth more to Vancouver in his chemistry with Pettersson than he'd be to any other team trying to trade for him. So among other reasons, that's why hei stays.