When a player signs for a club. Any club all you can ask is he does his best.
Not his fault how much, if any, that club has paid for his services, or how good he is.
He is bought presumably with due diligence being done by the club.
Or whoever represents the club.
If a player doesn't meets the expectations from a supporter, then that is not on the player.
It is on the supporter.
If the player doesn't meet the clubs expectations then that is different, he will be sold on.
But for a supporter to abuse a player because he doesn't meet that supporter's expectations is complete B.S.
It says everything about who that supporter is, and nothing to do with the player.