It’s really very simple.
If Haley sucks up to Trump and he wins, she’ll likely be appointed to a sinecure.
Harris isnt going to appoint her to anything, no matter how hard she sucks up.
And that’s it right there. To Haley, that’s the entire difference.
The donor class doesn’t really care about Trump’s mental (and psychological) issues, and really don’t even care much about Trump at all. They’re not actually supporting him - they’re supporting the handlers and advisers with which they intend to surround him, and the policies (and primarily Project 2025) that they intend to enact through him.
If anything, his incoherence is, to them, a benefit, since he’s just that much easier to manipulate. Since he can’t form a coherent thought on his own, he can be readily filled up with someone else’s ideas, just so long as they’re framed correctly.
He’s like a wind-up toy - all they have to do is feed him carefully crafted stories and get him wound up and pointed in the right direction, then just let him go.