Yeah, it'll distract viewers from the story when they think, "ugh, armpit hair!" if they see it done in a historically accurate manner. Better to keep them in the story.

Then again, sometimes you get viewers like my mother, who disliked Shakespeare in Love because it was unrealistic, she said, "Because Gwyneth Paltrow should have had hair under her armpits and she didn't!" Takes a particular sort. What a lucky daughter I am.