I was a little skeptical at first as well but I initially got involved when doing a career quiz and then by helping out with the Estonian chapter of Effective Altruism and I'll say that at least on an individual basis they're quite open to other thoughts and opinions and acknowledge that what they believe doesn't necessarily follow for everyone (ex. the idea that you can 'earn to give' - it only works if you have the personality type where you can do a job such as Ibanking and can satisfy your need to do good by giving and not actively participating as much)