What you imply is that all devs must be competent because they are devs. And that's not true. The lack of polishing, bugs etc. maybe obviously the budget factor, tmeline factor. But
desining complicated systems where the AI cannot process and will not be able to process it's a worng design. Let't take as an example warefare - the design is limiting the AI competency and good code cannot be alomst written (civ5 AI is still terrilbe today). Let's take another example - half of the great peple would need tons of code to process properly. Example - there is a great general which supports you units in certain era and than gives you ironclad. So only for that general there needs to be programmed: first following the fleet, and then when his era ends programing to go back safely with escort home. Lets imagine there is a naval battle with that general (hard too imagine, huh?

). How large should be escort? Player knows, but AI cannot consider it during that battle - should it go immediatelly with one escort (which will leave battle)? Maybe two? Shall all escort him back, shall it wait untill battle is ended (let's programm now the end of the battle). Is the way back safe and shall we avoid bomarding cities? This is bad design to have it done like here, not the lack of time or budget.
And really the game can be good or bad, and that's fault (when bad) of devs. Time and budget factor polishing. And what is pretty obvious, statements like "have they played the game?" are an exagerration of many people seeing their favorite title in state like that. The industry is like it is but if no one oposes and all give 9.5 to strategy game with completelly incompetent AI, it will be worse.
That claim is bold, and not just because I bolded it. First of all, I don't want to turn this thread into a 1UPT vs SOD debate, since it merits discussion outside of this thread. Most posters here are simply making a statement that not everyone lacks a grasp on what the words "alpha software" and "gamebreaking" mean.
But more importantly, what is more wrong than the design (your subjective opinion) is your belief that the AI will never be able to process 1UPT. It is always possible to code a better AI (objective truth). I raise you the Community Patch to counter your claim about terrible Civ 5 AI. Yes, it is not written by the devs, but by the community. No, that does not invalidate 1UPT. The fact of the matter is, an AI that can process 1UPT competently is already a thing, and if the community can do that, there is no reason to believe that a team of dedicated devs won't do that.
The bigger question is whether they are willing to put their focus on the AI. Civ 6 has another 5 years in its lifespan, and saying that they won't at 2 weeks into its release is nothing short of ridiculous. If you do take a look at Civ 5 patch notes since release, you will see that they had been improving the AI since release.
The fact stands that before the Community Patch, there was no satisfactory AI (and not just in combat, but also in most aspects of the game). But especially in terms of combat and 1UPT, the community was the first one that managed to make it work properly. What I am saying is, there is no point in making conjectures of how Civ 6 AI will (not) be improved based on the devs' track record of improving the AI during Civ 5's lifetime. Back then, the devs had to roll out patches that not only addressed the AI, but also prepare assets and ideas for expansion packs and other sorts of content, which Civ 5 vanilla was severely lacking. And there was no good example on how to code the AI for 1UPT.
The Community Patch was created by a team of volunteers who did not have to bother with creating new assets (not much anyway) or addressing the UI problems (the EUI team got that covered). Through their labor, for the first time we see how incredible 1UPT is as a combat system in single player, once the AI learned to be threatening with their maneuvers (not that the merits of 1UPT were not obvious to people who played multiplayer, but I digress). And this is where Civ 6 and Civ 5 differ.
Whereas Civ 5 created 1UPT completely without any prior insight on how to make the AI work with it, Civ 6 continued 1UPT in circumstances where a good AI for 1UPT already exists. And thus, while your claim might have been reasonable 6 years ago, it is not at the present.
So if a good AI already exists, why didn't the dev just port them from Civ 6? Well, most probably because while a lot of features were derived from Civ 5 BNW, it does not change the fact that Civilization 6 is an entirely new game. Aside from developing the obvious assets for the game, they have to code the AI to handle the many changes, such as city planning, new builder mechanics, etc. The AI is not particularly doing well right now, 1UPT or not. They sometimes fail to use their Great Persons, or to weigh the merits of diplomatic actions properly.
Will the developers make improving the AI their focus? Not sure, but it is highly likely. Civ 6 is more feature-complete than any vanilla Civ game ever released in the past, and therefore the devs can theoretically spend less time adding new features and spend more time fine-tuning it.. A fair criticism of the developers' competency can only be made if they refuse to improve on this highly criticized aspect of the game during its lifespan. And that lifespan is not 2 weeks.