It's hard to articulate, but it's that classing of a worthy foe or something. Like people say "say what you will about x but he does y good" (something said by someone about Rommel by Patton (at least in his movie))in a way that's meant to sound begrudging but just makes them sound like they want to be them if you get me
Witness it once in a blue moon
Which is fair, I don't respect extremists either, and I'm not saying everyone deserves your respect. However, society is all about limiting some rights to protect others. Inevitably there will always be different opinions on how to strike that balance. Not all these differences are worth fighting about, often it is much more worthwhile to talk to each other and work out a compromise. And that's much easier with some level of mutual respect.
Well in context we're talking about people who are willing to sacrifice people like me for the sake of civility and "hearing them out".