It's Mark Waid's fault.
He never really had any interest in Wonder Woman growing up, so when he got to writing Kingdom Come and had to come up with where she'd be in this darker future world, he basically went "well, she's from a superhuman warrior society, right? And she's a princess? So she'd probably have a sense of genetic and moral superiority over mortals, and since they're warriors it must mean she's fought and killed a lot, so she'd have a military commander's sense of practicality and a political revolutionary's sense of idealism ".
And despite this all being completely made up by Waid and Ross, not based on anything in the comics themselves, and literally the exact opposite of what Wonder Woman's creator envisioned her as, this is a depiction that stuck in a lot of people's minds because it was so different from Batman and Superman and there are so few other versions of WW to counteract it.