Just because he doesn't want to be with someone who is still married - not long into the divorce process, either - or has kids does not make him not a nice person.
Some people really don't want that.
When I was last single, I was separated for 2 years, then divorced, but after dating a bit, I really did not want to go out with a guy who was just split up except for flings because I was at a different point in my life.
And, being childfree, I defintely did not want someone with kids because step-parenting wasn't for me.
That didn't make me a not nice person, just someone who didn't want that.
Depending on age, however, some people want someone who's not been married before.
Also, tbh, if you're just split up, it's not a good time to be looking at dating beyond flings. Just my opinion, but something that comes up if you go to counselling and really, not matter how long it's been coming, divorce is a loss with lots of feelings that really needs to time to heal from before you launch into another meaty relationship.
I'm going to say please be straight with whomever you're dating.
I was at the point where I asked right away: Are you married, separated, divorced, just out of a long-term relationship? Do you have kids?
If I'd have been lied to, it would be a sign that's not the person I need to spend more time with, because they need to be confident enough to trust others to use their own judgment nad not take it personally if the other person isn't interested in a relationship with them at present.