There are two different forms of scientific history. The history of science as used for future scientific development lives in academic papers, journals, conferences, and similar; those are preserved as a record of historical development progress. That history is, when functioning correctly, blind to outside issues like this.
On the other hand, there's scientific history as captured by news and popular culture, which focuses on personalities, personal stories, struggles, and development. In that version of history, it shouldn't be at all surprising that people prefer to hide the crazy people and focus on those that can successfully serve as visible PR figures. That doesn't denigrate their contributions, but it avoids making them visible figureheads when they're not appropriate for a figurehead role.
You can complain about outside politics affecting science, but far too often, people like this will bring their politics into their science, such as in interviews and discussions; sweeping people under the rug doesn't just happen because of embarassment about past actions, but for fear of future embarassment. And that future embarassment can then cause problems when trying to get popular support and funding, which makes it entirely rational to focus on the scientists who can safely talk to other people.