I know what you're saying and again I'm personally invested in being kind to strangers. This is a problem to me-
…justify said bad behavior.
It's behavior. It's participation. It's like anything else personal: a personal choice. In a free and open (source) world it doesn't need to be justified. Disparaging it as sub-standard is little different from disparaging code as sub-standard.
Down vote, respond directly, participate as you like, etc, but don't be surprised if your desire to force conformity or to force others to agree there is a need to push it is perceived as rude by someone else. Like me (who upvoted everything in this thread, I think, so don't take that as a --; it's a reminder that everything offends someone). Free exchange is more important than perfect agreement, harmony, or avoiding (non-fatal) tussles.