From our personal experience;
Because they are an open, simple (for a current vehicle), small, off road capable and
fun vehicle. Some folks value fun more than outright reliability and other quantifiable attributes. The RAV Hybrid is a great vehicle for what it is, I have driven them, a wonderfully reliable appliance, but some folks want more of a driving experience than an unengaging appliance provides.
Is the Wrangler as reliable as your Toyota? No, not in anyone's dreams, and frankly we don't care and probably neither do most owners. Ergonomics on the Wrangler? Sub-par, we got used to them. Mileage? Same...aware of the obvious and not high on our list of concerns.
My Wife bought a '21 Wrangler Sport, manual transmission and windows, soft top that hasn't been up since mid June. Ours is a Cape house and beach permit car and is perfect for the role...I tried to talk her into an older NAS Defender, no luck. Of current cars, the Jeep (and I'd argue only the current Bronco) is the ideal vehicle for our use and met our wants.
People aren't stupid, well generally, and make their own choices based on their own circumstances. One basic lesson from B school marketing class (the principle also applies a lot to life); provide what people want, not what you think they really should have. Hardly 'delusion'.
Hmmm...then again, looking at my sig (and the Range Rover in the garage) I may not be the best to opine on this or anything involving reliability or sensible transportation decisions