In both third-party products and fan-created web sites, I am noticing a rather common trend: house rules and/or settings to make low-magic d20 games, whether it be D&D or a sub-system all its own.
What is it about the idea of "low magic" that appeals to so many d20 players? Has the gap between non-casters/partial casters and full casters become so large that a bunch of people have arrived to the same conclusion is to "nerf casters and/or make them more rare" in order to make "Low Magic" settings?
I once asked on the D&D boards how to properly make a low magic setting. One response was to not nerf PC spell casters in any way whatsoever.

The ability to spontaneously Create Water, hit an opponent without any attack roll (magic missile) are amazing abilities for 1st level characters, compared to the bonus feat that a Fighter gets or the Sneak Attack +1d6 for a Rogue. The way that magic is set up in D&D is that you would have to be a fool to not benefit from it unless there is some balancing factor, whether it be "Laws of Equivalent Exchange"-type thing based off of Full Metal Alchemist, or "Magic is evil and destroys you over time!" based off of Conan. Then I looked at the Black Company Campaign Setting's spell system, but the "Drain" factor, which involves non-lethal damage, is only dangerous when in combat or performing risky activities. However, seeing as how most D&D characters perform risky activities on a regular basis, it makes magic's limiting factor be the character's hit points, which is a universal limiting factor all around.
In short, does anybody have any answer to what makes "Low Magic" so popular, or how to make a d20 low magic game?