This is what annoys me most about DPC. The cleaning incident in the library is just a pointless excuse for replayability. To open this scene, you have to replay the game repeatedly and deliberately reject Bella in order to get this scene. DPC does not value the player's time at all.
And there are several such moments in the game that do not matter at all. Sarah's fuck in ep2 doesn't make sense in the general context of the story, because in the first two seasons there are essentially only two branches - the Sage branch and the Others and the Josy/Maya branch. Choosing Sage opens up an additional option later, and choosing Maya opens up a scene with her.
But the most incomprehensible case of dubious replayability is ep7, where Sage's fuck blocks Lily. It's funny that the short scene with Sage doesn't affect anything, but the scene with Lily opens the way with her.
You have to make your choice and mind between "replayability" and "he doesn't value players time". Because this things are mutually exclusive. You can do all paths in 2-3 runs (all MGs, all SGs and the rest you missed), split & save it further at the crossroads, but at the same time you will be always burdened with 3 or 4 broken girls hearts at least on the MGs branches. Each "right" playthrough are potentially exclusive - and it's both about replayability and playing "properly" and for the most likely happy end. So such motivations like scene exclusions here and there are works quite good, imo.
What's the sense to pick Bella or any other MG each time in your playthroughs if she is not your final goal? Lewd scenes? You can watch them 1000 times from gallery at any moment of the game. I mean, I myself have a "harem" and heartbreaking saves for the science and completionist purposes, but I don't consider them as my primary or the main ones. Even if you're quite short on free time, according to the current episode release times you may do a several playthroughs per year w/o any haste and collect 10-20+ of them totally in a few years to cover most possible permutations and outcome goals.
Same goes with MG/SG permutations. You have an option to create a manwhore saves and the clean ones even with a particular SGs.
Lily / Nicole paths have an options in EP10 if you pursued both of them, for example. And a lot of similar things and details here and there. But it's clear that the more girls you pick on board in one playthrough - the more things you potentially break and spoil and will soon or later have to pick someone.