No, you're confused. Civility isn't valueable because it's "moral". It's valueable because it's effective, Leftists aren't going to prevent conservative fascism by pure force of voting power. They need to do it by changing minds. And that is what "civility" can accomplish, and what other tactics fail at spectacularly. Anyone who's serious about being effective in their activism will use civility to their advantage. Whereas people who are more interested in impressing their friends will continue to claim that civility is just a sign of weakness or complicity.