It suffers from an ends-justify-the-means trap where bad actions in the short term with the long term goal of good actions are justified by the fact that you, the actor, know your philosophy is the best way to enact positive change.

I'm happy to try and get already wealthy individuals on the train of effective altruism but it has been used to justify wealth concentration far too much and, to be honest, spreading money around is one of the most effective ways to enact real positive changes in the world since individuals know their own situations the best.