Interesting observation from
@GleamingTheQ-Bert.
I wouldn't characterize Lucas's desire to reject people the way you do. I see it more as a general desire to wield power over someone.
"No" is a powerful word. Lucas is a powerless man, and hates it. He is dependent. Nobody takes him seriously. He has no control over his environment, or how people responds to him. Nobody does what he thinks they ought to. He has no one to say "no" to, nothing to exclude anyone from but his good graces and sexual targets. Lucas rejects women above the age of 24. Nobody notices or care.
Lucas is intimately familiar with rejection and social exclusion. He has been rejected, as a romantic partner, by Gen X, Millenials, and now Gen Z. He may long to switch up the power dynamic and be the rejecter, as opposed to the rejectee. But he'll never have the power of "no." So long as he has nothing that anyone wants, and covets what others have, he will forever be the one not invited to the party. And nobody wants to come to his.
Lucas is very vocal about his disapproval of Christians, liberals-in-names-only, flatbills, etc. He talks a lot about the people he is better than. He always presents his disapproval and superiority in such as way that suggests he believes it matters to his audience. When Lucas says something nasty about Christians, he expects them to take it personally. He makes the same mistake that many people do, assuming that his opinion matters. Or hoping that it does.
I believe that part of Lucas's desire to have a younger woman, and a child, is to experience power. Not the power of rejection, but the power of control and domination. He'd find that satisfying.
ETA
I’ve found this to be incredibly common in Borderline Personality Disorder. The insistence on being the rejectee not the rejected. They will contort themselves and their imaginary world to make sure the THEY are the ones doing the rejecting. Lucas has this trait as well.
BPD is one of the many disorders that has been ascribed to Lucas by armchair psychologists. Think of him as a BPD dude in a relationship with the entirety of Gen Z, complete with the idealization/devaluation.