However, Rounser, that only applies if you think that settings with giant holes in them are excellent.
To me, consistency is the goal. If the setting is inconsistent, ie. allows for the sale but not the purchase of magic items, then it is not consistent. There's a giant gaping hole there that needs to be explained and not hand waved.
What you see as making a setting slave to the rules, I see as actually examining how those rules interact with the setting. By ignoring or handwaving that interaction, you create a setting which has glaring inconsistencies. You can either change the RAW, which is perfectly acceptable since that changed RAW becomes the new RAW for that setting, or you can change the setting to conform to the RAW.
However, ignoring the issue doesn't make it go away.
On another note, I gave a bit of thought to RC's point about the WLD. Now, the WLD is a fairly simplistic dungeon. However, the inconsistent elements are explained in the book. Either it's explicitely stated that it is being handwaved (such as food issues) or it establishes new RAW (such as no web spells and no summoning). There is an attempt by the designers to at least recognise the inconsistencies and either deal with them or put a fence around them. They are not ignored. They are specifically called out. Thus the issue of food becomes a non-issue because the RAW of that setting says its a non-issue. The reason for it is entirely metagaming but, you can wrap it up in setting specific dressing if you like. The fact that it's an extradimensional prison allows you a lot more leeway in things like that.
Me, I added a bit where the angels performed a rite to kickstart a basic food chain. Fine creatures grow at a very high rate and are thus eaten by diminuitive creatures. However, nothing bigger than that can reproduce. Thus, no kobold babies, but, lots of mice to eat.
However, I didn't need to do that for the WLD to work. I did it because I wanted to. An extradimentional prison could simply not allow the inmates to eat or procreate similar to the Astral plane. I can apply existing rules to the setting and it works (sort of).
But, this illustrates my point very well. By examining those basic issues, I am looking at how the RAW of that setting affects that setting. If I don't like it, I can change it and that's fine. But, my point has always been, there should be an examination of the effects of RAW on a setting before the setting is finalized. If there are wonky interactions, then something needs to be changed. And it's that examination process which has grown out of the art of campaign creation over the years.
Yes, you can play a low magic game with 3.5 rules. You can't play a low magic setting with ALL the 3.5 rules though. To play a low magic setting, you have to change the RAW. This is a given. When a setting tries for a certain feel without changing any of the RAW it has glaring inconsistencies. The main example I've used is the existence of low level permanent magics. For gaming as an art form (wow, how's that for pretentious

) to grow, it must be self reflexive. Just like any art form, you have to have some sense of the theory of that art in order to move it in a new direction.
Yes, raw talent goes a long way. But, its those who have raw talent AND a grounding in theory who can really move things forward.