Quasqueton,
Very interesting question, I suspect that there is more than a grain of truth to some of the answers so far.
I played 1e in Wisconsin, Missouri, Indiana, Virginia, and Louisiana, mostly as DM, always using the same subset of rules and assumptions. I played 2e in California and Toronto, but as the system evolved so did the rules I was using (esp. once the Option books came out). I've largely rewritten 3e.
Even 3e, clearly written as it is, suffers from the problem of the "reader filter". When the reader reads it, he filters what is written through what he would have meant if he had written the same thing. This is not too dissimilar with the problems one can encounter on Internet messageboards, where a message as read means something completely different from what the message as written was intended to mean. I think that this is a big determinant in how one approaches rpgs, especially certain early rpgs with their stream-of-consciousness writing style.
People houseruled 1e because they thought some of the rules were too complicated, or unfun, or because they wanted rules that better reflected the campaign flavour they desired. I don't think, now that the blush is off the rose, that this is any different for 3e. Many people I know no longer play 3.0 or 3.5, but rather an amalgam of the two, with other houserules thrown in, including material from compatable sources like Arcana Evolved.
So maybe some of our arguments about 3.X come about because we're not really playing the same game here, either?
Just something to think about.
RC