It's notable that the "moralizing controversies" seem to be especially virulent concerning those series that I think of as "smut with something on its mind"--i.e., series like Asagi Ryuu's Age 15, Flowerchild's It's a Detached Relationship, and this one, that is, where the sex is depicted quite viscerally, where there are "problematic" aspects to the relationships (often age-gap), and where the setup implies a certain level of character development. (Or you could switch it around: "A Romantic Drama That Yearns For Smut.")
Such series seem to create a good deal of anxiety and ambivalence in many readers--hence the folks who (apparently) would be relieved if this series just went full-metal hentai. (I don't recall seeing many lemon-squeezing debates about the moral nuances of stories by Mira or similar shlick-fests, but I don't hang in those environs much anyway, so I could be wrong.)
And I agree that past MC, as recalled by present MC, was (is?) something of a romantic non-entity, and it's present MC's determination to stop being that non-entity which is driving the action.