The workplace is 8+ hours of most people's day. You cannot divorce it from the very real problems that exist in the world.
Advocating for equal treatment isn’t proselytization, it’s asking for treatment like an equal human being.
As a gay person in tech I have never felt oppressed or heard anyone else report such a thing.
If Basecamp was engaging in this kind of discrimination then the story would be very different.
If people had more time outside of work they could do this outside of work.