I think that entirely accounts for their initial rise in the ebike world, where "a look" means they want to achieve a certain appearance that they think is cool.The fat bike thing appeals to people who do not really ride bikes but want a look.
For me, riding a 2wd commuter that I pedal to a constant 32-34 mph, I have no trouble justifying those wider tires; particularly since I can't have front suspension for safety reasons. On trails, there's something to be said for just rolling over anything in your path without a care in the world - this being a bike with a job. Again, a commuter but in my case a commuter that takes a lot of dirt trails to the office if I have a bike that can navigate them. I don't ride them every day anymore, but when I do its a blast. I just kicked down my front chainring to 32T on my Big Fat Dummy so I can have a shot at running straight up the (empty... with full visibility) downhill runs that exist on the trails in my area.