Well, presumably the ideas we are talking about are political/social/moral views. To base your acceptance/rejection of them, even in part, on your knowledge of their genesis is already quite intellectually lazy. ("John made such and such claim about topic X. When I consider the claim's intrinsic merits I'm not complete sure what I should think, but given these biographical knowledge I have of John I accept/reject the claim" is only acceptable reasoning when X is an empirical topic (say about genetics) but not when it's a moral/political one)

If someone were to say to me, say, "Pot should be legal everywhere", and you tell me it's unacceptable when considering this claim to consider that the speaker is high, then I don't accept your bounds of acceptable reasoning. (Yes, knowing enough directly about pot would screen off this evidence. I think pot should be legal.)

For an X about how an individual wants to live their own life, that is up to them: it's not for me to "accept" or "reject" it -- though I might think they're making a mistake. I wouldn't privilege moral/political claims to the same degree.