If you're asking all these questions, you're trying too hard to "get" the game.
It's kind of a humor game, kind of a satirical take on how games in general just kind of expect you to follow along but in SP you can do all kind of "not what we're here for" shit like sitting in a closet for twenty minutes. Is it riveting gameplay? Not usually, but it was worth the $5 I paid for it. I certainly have gotten more than $5 of entertainment out of it.
Totally understand if that kind of game isn't everyone's cup of tea. I certainly wouldn't have played it in highschool. Or at least I'd be bored with it very quickly.
And with all the different paths in the game, replay is okay because you probably don't remember all of them.