First, because it would be part of a package, not player for player to happen. On the ice, the two players are worlds apart. Ott to me, is more then just a pest. Bill Berg was just a pest.
If looking at the Sabres Roster, why would you pass on Cody Hodgson? He is 23, and from Toronto. Why show preference in Grigorenko? I'd personally give preference to players from Toronto, and the GTA.
Guys who grew loving the leaves. Last yr, I very much enjoyed Komarov, but without the money we wanted, he leaves for Russia. I'm not saying boycott others, just preference to those local who want to be here.
So what exactly don't I like about Kardri? In a word, Inconsistency. He looks more and more like Grabovski all the time. He is young, strong, hits like a beast when he wants to and has great potential. But the downside I dislike is where is that emotion now? He drives in hard alone, and often stripped of puck. He does not do well in puck battles along boards, and will take poor penalties. When he does show emotion, he can't seem to control it.
Lastly, Kardri throws great hits, but can't take them. He is often bouncing off players, or picking himself up off the Ice. A sight Grabs would often perform nightly.
You say Ott is undersized, yet both guys are the same. When you look at highlights of the two, you see that Kadri are all highlight goals with a few big hits. Ott is more like how Tucker was.
Steve Ott highlights
At the end of the day, Kadri isn't going anywhere, and I'll always hold a bias/like to guys like Roberts, Clark, Tucker, Shanahan, Iginla, Lucic, Morrow, etc. Not goons, but sandpaper players, who will score too.
But the way the team is playing, and as guys return from injury, Kadri is far from a concern to address. He has lots of talent around him to allow his skills to develop more. As I mentioned, my only concern leaf is Ranger. All others are really doing well.