having them go to a building door and then what? doors open for them but you cant enter? or they just dissapear? People would complain about that so having them wander around is probably better.
Again, its not about the fine detail, its the overall scope. Seeing NPC's come out of a building is fine enough, V does not need to be able to enter, all players know that game's must have their limitations.
In order to see the dystopia, the mirror that the city is, the beautiful parts aswell as the ugly parts, the NPCs are scenery and they dont have to do anything complex. It would obviously depend on what you screenshot and exploring would be better but a set of screenshots can do the job, yes. And in that case the AI complexity or lack thereof, doesnt matter.
And that's the issue. You (and I assume others too) see the NPC's as scenery, pretty much mannequins that are just on scene/stage for a screenshot or to be in the way. To only "see" NC rather than be part of it. Its almost like its a film set (or worse, a tech demo), the NPC's wander into view, the shot is taken, move on to next shot.
However, maybe its because a lot of people have played games like GTA V and RDR2 and been exposed to that level of AI complexity they come to see this as the norm, or what AI should be since that AI makes those NPC's a bit more than set pieces for screenshots.
I think when CDPR said they wanted to make the game immersive, people expected the NPC AI to also be immersive and not just a minor feature, since they are part of the world in which the player is supposed to be immersed within, and a city without people is no city at all.