That’s a fair question. My most honest answer isn’t a very good one: I can’t stand it.

Linguistically, I don’t get it. “Fixing to” doesn’t seem to offer any benefit over “about to” or “going to” and as far as I can tell it doesn’t have any logical meaning at all.

Fair enough. I do think that connotation doesn’t necessarily carry over to the “gonna” and “finna” forms, but it’s a good point.

That said, “fixing to” still grates on my brain in ways I can’t begin to describe.

“Going to” is far superior to “fixing to,” so I don’t know what you are talking about.