Pretty sure it tends to be (for me, anyway):
Try #1: It isn’t going in. I’ve probably got it wrong, so I’ll try the other way.
Try #2: It isn’t going in. I’ll try harder. Huh, really seems not to work this way, so I’ll go back.
Try #3: Using more attention and determination, it goes in.
Try #1 often turns out to be the right way due to the cord having just been yanked out and left still in the right orientation, or muscle memory, or actually glancing at the keyed plug and remembering rightly which way the socket is. It’s just that the initial difficulty of lining a rectangle up exactly in several dimensions without being able to see (usually hand blocks view) and wanting to use minimal energy to do it, it doesn’t seem to work at first and flipping the plug feels like a good low investment of energy for possible easy payoff, compared to doing it all very deliberately.
As for criticizing USB plugs, there have been many far more annoying plug designs.