We are all different in our preferences of course to what we like, want and prefer. For me it's a matter of immersion, simple curiousity and finding quests etc. I hate limitations in RPGs and I prefer enterable buildings for the reason I mentioned. I get it that some don't and they prefer only relevant buildings are enterable.
In regards to explaining the immersion point it goes like this for me. If I stand in a sewer in a RPG and suddenly there's a gate or a rock in the way to go further I get this feeling I want to know what is down there beyond the corner. And I will look for anyway way arround it if possible. It's a matter of curiosity I guess.
In some games it is not possible to go further and in others you will get a key to the gate later in the game etc. It's the same things with buildings, houses and the like for me. I have this feeling of exploration and curiousity and then when it's locked or the door is not interactable just destroys the immersion for me when I can see NPCs wonder through it or appear just in front of it.
Or in other cases I see a window or a balcony and I want to get up there and view the city from it. And so on. When we enter Novigrad in the gameplay trailer I see many of these types ofplaces and it just fills me with a sense of wanting to explorer, just like I want to enter a dugeon or a ruin when I see it in the wilderness.
