I suppose that "incomplete" is a matter of perception, Civ5 had less feature on launch, I agree, but, for one example, at least the Civ5 AI knew that the game featured aircraft, even if it was using them badly, while we had to wait 9 months to see the first lines of codes related to aircraft in Civ6 AI (which still use them badly)Well, the person I was responding to referenced 'late-game improvements'. To me, that sounds like they want new content added to vanilla, for free. Of course I think we should get free bug fixes and tweaks to existing content.
Also, calling Civ6 incomplete on launch is a ridiculous statement imo. Both when comparing to previous Civ games, and to the current games market as a whole.
I can't call that kind of game "complete" on launch, not when a critical late game feature like aerial warfare is missing.
And, as a modder, there was some things that I could do with civ5 at launch (like controling the AI units, for a better use of aircraft in my WWII mod for example), that I can't do even one year later with civ6. On that side it's far from complete, for another example, just compare civ5 and civ6 Worldbuilders...
Now, from the start I've seen a lot of potential in civ6, and today I do believe it will be a great game, superior to civ5, and maybe it will even be able to compete with the great memories I have of civ4 (and that's telling a lot as every one knows it's difficult to compete with a memory of the good old days...)
Civ6 has progressed a lot in one year, true, (even if I'd love to see it progress faster) but IMO the diplomacy AI (I'm not talking adding a "World Congress" but better handling of available diplomatic actions) and the UI are not worthy of a released product, just an early access. That's the kind of "improvements" (we could add the combat AI) that are not simple bugfix neither completely new features that we're surely expecting from an expansion and should be ported to vanilla (and, for the AI code, were for civ5, from my memory of the patches to the source code)