Look at the Andrei Mironov experiment to see how bringing over a supposed NHL ready established KHL player went. It's a lot of pressure on a player to adapt to the culture, lifestyle, language, ice surface and being in a NHL organization, system and coaching all the while saying they better fit into the NHL right away and keep a job from day one or else. Stagnation and getting buried in the minors for too long is a concern so I get that but it isn't just an issue with foreign players.
Anyway back to Kamenev, he has looked better and better as he's got comfortable. Looks like he's earned the 4C role for now which is good, it's a consistent role and he gets time on both special teams units.