There wasn't one.
"Selling out" of D&D has always ocurred at the corporate level, and that didn't start happening until Gary was swept aside by Brian and Kevin Blume and they began to wreck the company financially: buying a needlepoint business (now one of you collector types find me a TSR produced needlepoint kit, and then I'll be impressed!), hiring on over one hundred additional employees (most of whom just got paychecks), the fleet of 100+ cars that TSR acquired.
Oh, and then the legal shenanegans when Gary got back to Lake Geneva and stopped the Blumes from dumping the now-nearly-worthless TSR on "the Street", maneuvering Lorraine "I am above gamers" Williams into power, and attempting to put Gary in a legal position that would forbid him from using his own name publicly with TSR's consent first, despite the fact that he was already gone.
You decry UNEARTHED ARCANA from this era as being a "sellout" but do you know what? You're right, it did "sell out". It sold out of every hobby store it was shipped to. It was a runaway success and the fact that there still is a D&D hobby/game is the net result. What was Gary to do? Let D&D die? TSR was swimming in debt and they needed money, fast. The fact that Gary's name was on a rulebook and that it completely turned the company around months after publication should tell you something.
Am I crazy about the rules in UNEARTHED ARCANA? Nope, I sure am not. But I recognize what it was in the overall, now, with hindsight. Furthermore, as a Dungeon Master I'm free to use, abuse or ignore the rules in UNEARTHED ARCANA at my leisure. I hail the book for doing two things: keeping the doors at TSR open, and rubbing the Blume's face in the simple fact that as much as they were a couple of MBA holding greedy sons of bitches, they'd never be accepted by the people - us - who bought D&D stuff. Gary's name on products sold. Hell, compare sales of UNEARTHED ARCANA to later volumes (THE WILDERNESS SURVIVAL GUIDE, MANUAL OF THE PLANES, THE DUNGEONEER'S SURVIVAL GUIDE).
Heaps upon heaps of late 1e books moldering in TSR's warehouse (mostly those last volumes...), dumping money in to salvaging some lake-boat (which as it turns out was entirely decayed - wood rotted, metal rusted away), putting profit over people - that is when the sellout occured.
Ryan Dancey wrote an impassioned letter to D&D fans about how he was in charge of "saving" the game, if not TSR. Just like UNEARTHED ARCANA before it, the d20 system, the OGL and D&D based on d20 did just that.
Now that Hasbro calls the shots, the selling out continues forward: I don't think there was a need for the endless flood of MONSTER MANUAL books, splatbooks, class books - basically all the stuff that was done in late 2e that they told us they were getting rid of, never going back to, etc. That's another sellout.
But to try and pick one point in time and say "Well at this point D&D had no soul" is a bit disingenuous. D&D has a soul every time I spend a couple of hours late at night after the house has gone to bed, putting myself in the mind of god-creator and deciding what Erac's Cousin is going to do to try and stave off the adventurers for another week.
With all of that said, I find it equally disingenuous when some people claim that the current incarnation of the game just makes everything good - that bad players, a bad DM, and bad source material through some divine miracle of the current ruleset become great. Rules don't make D&D great, or lousy. The people do. There is no golden ruleset that makes D&D perfect. None. I love ADVANCED DUNGEONS & DRAGONS. If I can't convince you to look at the DUNGEON MASTER'S GUIDE and not just sneer and say "that's a pile of broken, illogical, unworkable rules" or "what a horribly disorganized mess", then we don't have a lot to talk about. If I tell you I love ADVANCED DUNGEONS & DRAGONS and your response is that I can't really have fun with it, that I'm only playing out of some bizarre sense of nostalgia, then I don't think we can really have a civil conversation about D&D.
But if you and I start talking, rules agnostic, about things GREYHAWK or that one time in B2 KEEP ON THE BORDERLANDS when the thief backstabbed the owlbear and saved the party, or sneaking in to Nosnra's hideout, or painting up minis, or dice collections, or meeting Gary for the first time (with the caveat that you're not a hater), or your first GenCon (gotta go to that someday, if only to shake my cane at you young punks see what it's like)...then DUNGEONS & DRAGONS hasn't sold out, regardless of what some idiot in a suit in the Corporate Office says or does (and I don't think Gary Gygax, Peter Adkinson or Ryan Dancey were idiots in suits).
