Why does Falcon want to negotiate with Karli?

Scarlett Witch maybe had a hand in killing a few hundred people, though they do say iirc that the rampaging Hulk didn't kill anyone just caused massive property damage most of which was Tony's, but she in turn helped prevent an extinction level event which saved the lives of billions...she paid her "debt" before she was recruited, this chick not so much, maybe if Zemo tries to release a virus which will kill any superhuman on the planet or potential superhuman there by risking the lives of possibly millions even billions and she stops him she'll earn some good will, but until then not so much.