I don't get the backlash. The specific goal is to limit spell casters in general and specifically for a low magic game. In that case: "Boo that sucks, I'm playing barbarian" is a desired outcome.
But they will still have all their spell casting, just it is more onerous to use it in combat. D&D is not just about combat... spell casting classes would still be extremely effective in exploration endeavors.
It sounds like you just dislike the premise, which is completely fine but the original poster specifically didn't ask for that kind of criticism.