CleverNickName said:
Perhaps "worry" was too strong of a word. What I meant was, this doesn't appeal to me. I don't want to have to keep buying books in order for my rules to stay "current."
Then you'd better find another hobby!

Incidentally, I must state that you're the first (if not the
only) person I've ever seen demand
less errata from publishers
Seriously, though, incorporating errata and rule revisions into RPG rule books between printings is standard practice and I can't think of too many publishers off the top of my head who
don't do it. It seems that it might simply be an out of sight out of mind thing, in your case. That is, It seems that when you weren't aware of the practice, it never bothered you in the least, but now that you know about it and are aware of it, you don't like it at all.
To wit, WotC has been updating the core D&D books in this manner since shortly after the release of 3.0 -- I had at
least two different printings of the D&D 3.0 PHB, one of which was a first printing with expanded quick play rules and plenty of errors; the other of which was a second printing, which was missing the quick play rules but incorporated a good deal of errata. While I didn't buy further copies of the PHB, I am
certain that the subsequent printing were handled in the same manner.
Even the AD&D 1e books were updated between printings*. Here's a look at changes in the
Monster Manual and
DMG*. Many newer games like Shadowrun 4e have already seen multiple printings (I
believe that it is on the third or fourth printing) with errata incorporation. The practice even affected the original D&D woodgrain and white box sets. It's literally been applied since the beginning of RPGs and continues to be applied to this day.
I know that it has its advantages, and I know that it isn't unique to 4th Edition. . .
The point is that the practice of incorporating errata and rule changes between printings and without declaring a new edition isn't just
not uncommon, it's the way things are done (and have been done for decades) in the RPG hobby, with
very few exceptions.
If a publisher had to declare a new edition of a game any time that they wanted to incorporate errata into a book, they'd go bankrupt very quickly. Just look at how much turmoil an edition change every ten years or so creates!
I'd rather they release one set of 400+ page rulebooks every 7-8 years, instead of releasing a collection of 150-page ones named I, II, and III every other year.)
Wait. . . I may have misunderstood (but I don't want to waste all of the elegant explanation). Are you saying that you have no problem with publishers incorporating errata and rule revisions into subsequent printings of the
same book but, rather, that your issue is with publishers printing
companion volumes (e.g., PHB II) with additional information and the errata for core volumes contained therein? If so, that's quite different.
*Oddly, while the AD&D 1e PHB errata was released, it was never incorporated into any subsequent print versions of the PHB (so there are some unusual exceptions to the rule).