I'm genuinely curious about why this is a thing, like in general. As someone else just noted, there are existing tools that allow the user to turn it on, which anyone who really likes having rollback has probably already learned how to do long ago. So if they want the rollback, they're gonna have it anyway. What do you gain by not having it on by default? The bit of feedback I would offer is, of all the times I've played a ren'py game that had the rollback disabled, 0% of them were more enjoyable for me because of that.
Is it a programming thing? That's something I would have more sympathy for. If having the rollback enabled causes extra programming steps, then I can appreciate wanting to bypass that additional effort. But if it's a matter of how you want the game to be played or how you want other people to experience the game, why not let the players decide that for themselves?
You're presenting this as if my choice is the weird one, but I'm going to turn this back around on you. Practically no commercial VN outside of a subset of erotic VNs made in the west supports rollback. Even commercial VNs made in Ren'py disable this functionality. So why do you come at the is with the angle that I'm making a bizarre choice when I'm simply following the standard? The lack of a History menu is admittedly an oversight that will be fixed as soon as I can (which means the next version, basically), but apart from that...
That aside, my thought process is this: The current version offers no mid-chapter choices that would justify rollback. The only reason to use such functionality would be if you missed a piece of text, which History will solve (in an industry-standard way, too). The short chapters that can all be replayed easily give you an additional way to catch up on things you might have missed. In fact, the density of the writing and lorebuilding in this game encourages you to revisit previously played chapters to see them in a new light based on information you have learned since the first playthrough. On the flipside, rollback causes a bunch of issues. Worst of all would be if a bug causes it to activate in relation to the card game, because that will fuck your game up in ways that could permanently mess with your persistent save. But even in the story chapters, rollback causes issues with a lot of things, with video sticking out as a particularly sore point.
Rollback causes a lot more issues than it solves in this game. There is a place for it in some types of games, such as Long Live the Princess. But in Supermodel as the game currently works? Nah.
Use Ren'py hacks to enable rollback all you like, but don't tell me I didn't warn you when it fucks up your save.
Can you list any future tags you will be adding?
I'm sorry, but I don't think that's a good idea. I'm not attacking this project as a fetish game, so I'm not really aiming for particular tags. You can assume that the usual suspects (vaginal, anal, cumshots, among others) will be here, but I'm not ready to predict any others just yet. I want the porn scenes to develop naturally during the story, not because I'm working up to something specific. Well, outside of very unusual circumstances, that is.
Do keep in mind that Supermodel isn't a porn-focused game. There is even a button in the preferences to disable the porn completely (intended for YouTube and Twitch streamers, primarily), and the game should still be more than worthwhile to experience in this form. So porn tags aren't really at the top of my list of concerns right now.
I wish I could be a little more helpful on this, but I'm afraid I don't really have a better answer right now.