Richard Stallman and the GNU project

Of course it doesn't, and you would be hard-pressed to find someone who disagrees with that assessment. However, Jefferson and the Ancient Greeks held slaves at a time when this was the societal norm, and this continued to be the societal norm for many decades (or even centuries) afterwards. They did not and could not suffer any slavery-related scandals during their lifetimes that (however irrelevantly) would have tarnished their authority on other matters. Their reputations as political and philosophical greats in their respective fields were safely cemented long ago, and are not today in any danger of collapsing even though society's attitudes have shifted rather dramatically.

Stallman, by contrast, is still alive. Rightly or wrongly, his general behaviour can still influence how others see the ethical-technological views he espouses. As its founder and its most visible and vocal representative, any scandal involving him could be used, illogically but not ineffectively, to discredit the entire free software community.