There's the 'macho image,' "I'm an adventurer because I own a Jeep, or a Toyota Landcruiser, not a Volvo." In Australia you used to see signs on the back of trademen's pick ups saying "Real men don't drive Volvoes" (Volvoes were reputed to be the safest car on the road at that time)
Also, I think the big, off-road vehicle took off in city and suburbia as an 'keep out of my way, I'm bigger than you,' statement. The belief being that in the heavy press of traffic we now have on our roads, it would give the driver some sort of psychological advantage. "If I collide with a sedan, I'll get a little dint and they'll take all the impact. Oh, and to make sure it happens that way I'll fit a big bull-bar on the front. Yeah...they'll stay clear of me."
Unfortunately, if two big off-road vehicle collide there's big trouble. Neither will crumple and so the passengers and drivers risk far severe injury if not death.
Still, the feeling of "If I'm in the bigger vehicle I'll be safer," and generally this is the case. Way back in the mid 1970s I used to drive a truck. For sure, I felt a lot less vulnerable than if I were driving my little four-cyliner Morris.
So it's a mixture, of being 'macho' and feeling safer at the same time, I guess.