It really does, in fact, work that way. Vulgar language is pretty common both in OSS and, perhaps surprisingly, in private codebases. I assume you don't subscribe to LKML, or have never read the linux kernel source? grep -ir fuck in linux, you may be surprised at what you uncover.

I understand your point and on a personal level I agree. I maintain a level of professionalism in my own work. I find that kind of language ultimately unproductive.

However, the OSS world has a good deal of engineering talent that swears like a sailor and is, at the same time, quite successful. This is simply an observable fact.