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
That's only because they themselves want to be respected and they want those they like to be respected. They will never actually respect those they don't like but they will demand respect regardless because they are "always right" in their minds.