That's not addressing the problem, that's trying to pretend like they're taking action while not addressing the root causes of anything.
Exactly. Nothing actually changes. The "support" is superficial, but it's still support, as it influences the general public. And the reason it won't create any meaningful change is because BLM are part of the system, and not fighting it. If they threatened meaningful change, they would not be getting the support they get. It's worth noting that political statements are banned in football matches here in the UK, the England team recently got fined for wearing poppies, a symbol of remembrance for the war dead. Players can be fined for publicly supporting the "wrong" kind of politics. That players are allowed to do this without consequence is a statement in itself that the system supports their actions.

Most people who "support" BLM are either politically manipulated, or motivated by money.