Why do they do it? They know that coaches are problematic and ignore all the signs and complains and keep the coach in the team despite that kid after kid decides to leave or not even sign up with the club because of the coach's negative traits.
Case in point, FC Valencia B07 Blue. Over the last three years, the coach (Carlos Santiesteban) has caused problems with his decisions and with his bad handling of situations and with his favoritism and yelling without teaching. Kid after kid has left. Parents have complained and Charles Martinez gets all defensive and tells parents to leave if they don't like it. Well, finally, the team exploded and 6 kids left the team in the last two months. Even the two most ferocious moms who protected the coach because their kids were the favorites decided to leave (I guess Carlos started yelling at their kids and couldn't take it while looking how he did the same to other kids over the years).
Charles Martinez is aware and instead of removing the coach from the team, he's keeping him and calling for more tryouts. It's unbelievable.