They might have not done anything wrong per the rules but you can't be surprised people are mocking Barcelona because of the terrible way they have done business by bullying.
Bullying? I'll assume you're referring to Leganes and the Braithwaite since that is what you originally posted and that is what I applied to.
--So first and foremost, as you admitted after I pointed it out to you, they did nothing wrong per the rules. I'd say it should be painfully obvious, but the rule is there for a reason and was used for
that exact reason.
--Second, they paid the player's buyout clause. Again, a "rule" that is actually a requirement in Spain and unless you have evidence to the contrary Barcelona either A) paid said clause or B) agreed a deal with Leganes. So if it is A, they did nothing wrong.
--If you're so concerned with Leganes, and I doubt you are, then you should have a look at Leganes' role here themselves as they played a large part in Braithwaite's clause being what it was.
--Furthermore, if you want to look to apply blame further, have a look at the player himself who surely also played a part in the clause being what it was and who agreed to the contract that included the buyout clause.
--And if you're still not satisfied, suggest some changes to the rule, that make it more "fair" for lack of a better term, up to and including elimination of the rule altogether.
At the end of the day I'm not surprised someone would bring up the Braithwaite transfer because people post stupid things on this forum all the time.