It's mostly about gender roles. There are vanishingly few men shorter than you, so that's probably why you don't get it; basically all men are still taller and gender roles are still maintained.

I'm not trying to pick on you, so I'm sorry if it comes across that way (and I'm afraid it might, hence this disclaimer), but yeah, most of the opposition to short guys stems from the cultural de-masculinization of male smallness, and that isn't as big of an issue to very short women since most short men are still larger than they are, so women your height typically don't see what the issue is.

But if you were 5'9"? You probably would at least understand why some other women aren't interested in short men.