Let's be honest, with current speed of development such game would be a decade long project if there was slow "farming of trust points" of all girls and first HJ scenes we would watch after a year that was solely focused on one girl.
In the past, I wouldn't have minded the slow development of a relationship, but now after playing many adult games I am tired of slow developing relationships and want fast move and focus more on "later" part. Personally I would like to see more of a proper "harem relationships", now it's more like MC have multiple separate girlfriends and not a harem, same feeling I have with ZR1.
Ultimately, this is the path the developer want to take. If you like it, fine, if not, there are other games you might like better.