On the subject of DNF, it would only have been a positive step, had our beloved Yahtzee been in charge. Then again, it would have been a positive step had a lobotomized monkey been in charge of the whole thing, so ya.
I could see there be a lot more "have I mentioned I'm not gay" from Duke, had Mr. Croshaw been writing

"No, these twin schoolgirl strippers aren't overcompensating for anything. Why would you even think that?" in a cheeky British accent.
.
On the subject of sequels, file me under "I don't get it." I don't get why every game MUST have a sequel hook and a direct followup. Why not follow the RPG strategy (Final Fantasy, Elder Scrolls, Diablo, etc) and just make completely unrelated sequels in a somewhat similar universe.
For example, if Bioshock had gone straight from #1 to Infinite, I'd be much more forgiving. You can still call it BioShock and thus remind people of the awesome game you already made in order to draw in your loyal customers. But at the same time, put it in a completely different setting with completely different characters. You can make some lore tie-in, if you're so inclined, but let games end. Let the stories be told, give us closure and leave it at that. If you want to do a trilogy, set it up as such from the beginning and don't try to shoehorn in a sequel where none deserves to be.
Worst case scenario, your sequel gets delayed over a decade and becomes some crazy internet phenomenon, at which point the FINALLY released sequel sells well enough to pull a profit despite being complete and utter crap. And on the subject of DNF: FULL CIRCLE BABY!