Thanks for posting this. I am (was) a "gamer" from pre-3e myself and from looking at various boards in recent months I've really wondered this myself...so now I'll throw in my 2 coppers.
I don't recall us EVER having debates or complaints about "balance."..and we DID get into some higher levels...think my high school group was averaging levels in the mid to high teens...that's what I think of when I think "high" levels.
All of the time and energy and product after product after product, forum after thread after forum, talking and gravely concerned with "balance." It just baffles me.
The game is (or should be) balanced among the players (and DM) themselves. Everyone's good at something different...the fighter fights, the cleric clerics, the thief thiefs, etc. etc. I understand "Oh gods, the mages get soooo powerful."...Yeah, I guess they could be...when (if ever) they're over 8th-10th level or so. (or used to be...who knows what level with the game as it is now?) And it took, if memory serves, PAINFULLY FOREVVVVER to even get to 5th!
At the same time, at/around 7th-8th level, the fighter was laden with magical armor, weapons, massive hit points and most likely strength enhancing magic items. Thieves had a bevy of items (probably something for invisibility or flying or climbing or silence...if not all of the above), greatly heightened stealth skills and (probably) amassed riches they could have accrued by then. Clerics got their butt-kicking spells too (along with the magic armor and weapons and items)...soooo who was so much more powerful/unbalanced than whom?
I don't see how mages were so outrageously "overpowered" or making the game "unbalanced" as seems to be the common consensus.
BUT, as I've said before, I am sorely out of the loop when it comes to actual game play for a few "editions" now...so I'll leave that kinda analysis to the mechanics & rule-mavens to hash out.
For me, the game (D&D or AD&D or OD&D or however you want to label...pre-3-3.5) was always more about imagination, story telling and character CREATION (as in developing a Character, capital "C", not just the rolling stats & pick a name part) than feats, scores, "balance" or character BUILDS...Oh yeah...and FUN. It was about fun and being social too.

"Balance" never really entered the equation.
Just my thoughts.
SD, the great and powerful, has spoken.
That is all.