The fundamental problem is that Effective Altruism is a political movement that spun out of a philosophical one. If you want to talk about the relative strengths and weaknesses of consequentialism, go right ahead. If you want to assume consequentialism is true and discuss specific ethical questions via that framing, power to you.

If you want to form a movement, you now have a movement, with all that entails: leaders, policies, politics, contradictions, internecine struggles, money, money, more money, goals, success at your goals, failure at your goals, etc.