I do worry about “ends justify the means” reasoning when evaluating whether a person or project was or wasn’t “good for the world” or “worth supporting”. This seems especially likely when using an effective-altruism-flavored lens that only a few people/organizations/interventions will matter orders of magnitude more than others. If one believes that a project is one of very few projects that could possibly matter, and the future of humanity is at stake—and also believes the project is doing something new/experimental that current civilization is inadequate for—there is a risk of using that belief to extend unwarranted tolerance of structurally-unsound organizational decisions, including those typical of “high-demand groups” (such as use of psychological techniques to increase member loyalty, living and working in the same place, non-platonic relationships with subordinates, secrecy, and so on) without proportionate concern for the risks of structuring an organization in that way.
There is (roughly) a sequences post for that. :P