I wouldn't blame anyone, if truly that Barcelona players concluded that the management shouldn't bring in Rashford, because assuming Rashford is a superstar, all players and clubs will want him in their side. Rashford didn't value himself neither did he take his career serious and that has led to this. I don't think that the players want only Spain players to be in Barcelona because it is not possible since there are other players that aren't from Spain in the club.
Despite the opinion that only Spanish players are in control of Barcelona, the fact that not only Spanish players are currently in the Barcelona squad is actually enough to make this statement in the end.
Rashford's condition is not in good condition with the current price it seems that this is only an issue to increase traffic because after all even though in the end there may be some protests by some players but when talking about the club in the end the absolute decision is certainly in the management not the player.
On the other hand, all forms of speculation may be discussed, it's just that I'm not sure if in the end the main reason only refers to the Spanish players who are the reason because of Barcelona's philosophy even though from the beginning there were more Spanish players but that is not the philosophy they adhere to.