I think you underestimate the fans/D&D gamers. I don't know a single person who plays casters that think it is a good thing that this disparity exists or want to keep martials down 'so they can feel special' (honestly, the people most avid at keeping martials constrained seem to be people who want to play very mundane martials). Instead I think it is a fundamental issue that caster stock rose when their limitations* disappeared, martials did not get a commensurate boost at that time, and most things that have been put forth to boost martials** violate someone's sense of what a fighter is.