I think it's evolution, not a desire, or tendency to be 'cool'.
Is an 18 shot M&P more effective, cheaper, vastly more reliable, and easier to master than 98% of everything else?
Is AIWB easier to hide, more comfortable, and quicker whilst on your back fighting for your life than anything else?
The cavemen weren't blasting Mastodons with a .338 lap. magnums right? Of course not, that doesn't mean that a well placed Lapua Magnum is not a better option than a club, right?
Evolution.