For what it's worth, I think you're right about the common-carrier argument. If that's not the argument you're making, disregard my support.
A lot of these folks, in their reasonable zeal to prevent somebody on the internet having their feelings hurt or being made to feel scared, are ignoring the global costs to their chosen fuck-you-got-mine strategies of selective communications. A minority would be even happy to let, say, a misogynist with a cure for cancer be panned or banned irrespective of their other positive qualities. They can be hard to reason with.
Why is it a surprise that the people making these privacy tools were motivated by a desire for communication free of the chilling effects of violence?