Plenty of people enjoy their horns stock, others enjoy modded. Now, what exactly is wrong with horns, seems like all these people are satisfied. Unless we're all masochist and only fooling ourselves.
Perhaps the ease with which horns are amenable to diy or off the shelf mods is part of the appeal.
By the way, I've modded box speakers, open baffle and horns, I like my speakers to fit my exact needs. Nothing inherently wrong with any of these designs.