Hmm... where to start.

At least BSD side, a lot of people *are* LGBT. Most people are quiet
about their personal life so I won't advertise that fact, but at least
Kirk McKusick (author of BSD FFS, FreeBSD) is very open about his
relationship with Eric Allman (author of sendmail).
Is it surprising that they get upset if you spew hatred against LGBT

Eric S. Raymond has to ask himself why he hasn't needed to know that
contributors are women. My own name is unambigiously female. If
you've seen a single commit or reply by me, you already know that I'm
probably a woman.

In a tight-knit community, it's really hard to miss big aspects about a
person. I know my friends are gay because they mentioned their partners
names which were unambigiously gendered. They also go together to
conferences. I know my friend is trans because she discussed the travel
difficulties following changing her legal documents.

What happened is that Linus Torvalds finally realized that when he
sends an email to the Linux mailing lists, there's at least a few
hundred readers.
It would be far more beneficial to the project if he toned it down
with the abuse.
Seeing another person abused is like hearing your dad scream at your mom.
Yes, you're not the one taking the abuse, but it makes your home life

I've been rude to others as well and it has occurred to me that as one
of the loudest people in NetBSD, I make a big difference in the overall
tone in discussions. I'm replying to hundreds of bugs made by people who
otherwise see little interaction with developers. If their experience is
positive and they are treated with respect, they are more likely to make
an effort in the future. It's my obligation to the project to leave and
calm down when I get upset.
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