If there's a door there, it should open. If it won't open, there shouldn't be a door there. How hard is this? Putting a door there that's never going to open just frustrates the player and destroys the suspension of disbelief. It reminds them that they're not really in this world they can see, they're in some arbitrarily limited construct devised by a "product manager" at some company to try to screw a few bob out of them.
What kind of world do you live in that you're able to open every single door you see? You actually believe that is realistic? Especially for games like the original Half Life, set in this huge commercial / industrial type top secret research setting. I would expect that EVERY door would be locked by default!
The complaint is more that IRL, there is *some way* of opening every door out there. Most of the time it's out of simple respect of what a locked door indicates that you don't even try. The rest of the time it's usually that the effort isn't worth it. But it's totally possible to open every single door in, say, a hotel. In many games, doors are just decorative, despite that there's an implication of something behind it.