I believe Dries's words in his apology post were sincere, so I do submit that as evidence but understand you may find him untrustworthy. However, the willingness of people who practice BDSM who actually work for him to speak out on that post provides even more compelling evidence that Dries isn't known for discriminating on that basis:
If Preston and other BDSM practitioners like him are fired from Acquia or removed from the Drupal community, I'll eat whatever crow you care to dish up.
Unfortunately some kinks are judged harsher than others. For example, if someone got sent a picture of their employee engaging in some flogging or even caning in the privacy of their bedroom, it's unlikely they'd care - but e.g. a branding ceremony? Needle or scalpel play? Presence at a high-protocol, strictly gendered event (e.g. male clothed, female nude)? Making a speech at a wedding between people in a relationship based on power exchange, that touches on the inequalities those people have chosen to make part of their relationship? All of those things bother some people a lot, potentially to the point of severing all ties that they legally could.
If he has harmed someone in the community or been put in a position to harm someone by his place in the community, you'd think Dries would be able to say that. If there's a police investigation or court case sufficiently far along that Dries thinks it's likely it happened, you'd think he'd be able to say that. But he's said absolutely nothing aside from his vague "because equality" statement.
http://buytaert.net/comment/132641#comment-132641
If Preston and other BDSM practitioners like him are fired from Acquia or removed from the Drupal community, I'll eat whatever crow you care to dish up.