I can only hope, but I'm a woman so you'd have to ask the men around.
My husband told me before, (and I know he still feels this way) that if we were to ever split and he were to date an OW, if she did not take to the kids - and they to her, she'd be out the door. I felt the same about OMs.
I can only assume that a man values the mother of his children in some honorific way. I sure hope so. (I admit that there may not be the same "need" of parenting from a stepmother, b/c the kids have their own moms, but that's not really the question you asked).
I think it's safe to say that a "bad mother" would be considered pretty bad news.
M: 57 H: 60 M: 35 yrs S30,D28,D19 H off to Alaska 2006 Recon 7/07- 8/08 *2016* X = "ALASKA 2.0" GROUND HOG DAY I File D 10/16 OW DIV 2/26/2018 X marries OW 5/2016