Chances are chances. As I said it is certainly not the type of player I would sign, and I'm not sure Koeman had any clue what he was getting himself in to, but at the end of the day Bolasie created chances and goals at a more than acceptable rate. He got hurt. That's why it stopped.
I'm all for beautiful football, but the end result matters too. For example I was going through some of the games just now and the game where we drew Swansea 1-1 at home on the late Coleman header includes a Lukaku miss from about 4 yards out from a Bolasie cross. It came from him almost falling over, doing three unnecessary moves and fizzing it at knee height, but still it's a shot from 4 yards that he set up. That was kind of his game, really ugly at times but ultimately capable of doing his job. This was two games before he got hurt too.
So to me, acting like he was "doomed from the start" or "never useful for anything" or whatever else goes around whenever he comes up is just too much in my opinion.