I think it’s two things.
1. It’s really hard to assess the level of some of the players when they play in a team as bad as this. Football is a relations game and things like positioning and tactical understanding are so dependent on functioning relations. So for instance a player may seem to be out of possession in the build up for a goal against, even if he is actually just doing what’s he’s supposed to do. Add to that the confidence factor and insecurity that comes from losing all the time which easily can affect a player’s overall game from carrying the ball to passing and shooting.
2. There’s a difference between criticism however harsh and scapegoating. That’s what you’re saying as well, I think. But the former can be overdone and become the latter. I think that’s what some people think happens here. With my first point in mind, any player can look horrible if you put him under a microscope and don’t consider context.
For me this means that an informed opinion of a player’s general ability needs context, ie. not just the eye test. It’s stats, team form and, in VK’s case, the fact that he did well in a strong league last season - and yes, his attitude and fighting spirit as well as that is always a good indicator of a player’s chance to improve.