mystral: I'm not sure a store that sells games like Master of Orion 3 or Might & Magic 9 can really make much of a claim about having good quality control. ^^
Not to mention there are also a few games that are pretty broken for many users, like Interstate 76.
And tbh, I don't really care about quality control, or the utter lack of it on most online stores.
From my point of view the responsibility of making sure you don't buy awful or broken games lies on you as a consumer. It's not that hard to do a bit of research before buying a game, really, and considering tastes in games are highly subjective, I don't like the idea of stores being very selective about what they sell.
Declining games as unworthy due to subjective appraisal is uncool, I agree with you there, and in some instances GOG is rumored to reject games on subjective reasons (perception of low sales, developer not marketing, etc). Games for sale should offer seemingly fair content and with consistent advertisement. I think it possible to develop objective criteria for what a publisher (GOG) would allow in (hypothetical) early access for consumer protection. It's up to consumers to research before they buy, but vendors should also be accountable to fair ethics - not just slapping whatever is up for grabs on the shelves.
GOG's money back guarantee and catalogue free of obvious buggy releases shows me they ensure games are operational regardless of content (and GOG has some turds on their store). Interstate '76 may be an exception in that it's incompatible with more modern systems; but to GOG's credit the game card clearly shows that it will only work on Windows XP or Vista so there's no deception or unexpected dysfunction.