PC-88 Sorcerian is basically my childhood. It’s one of my favorite games of all time. I understand what you’re saying about the scrolling, but I don’t think it’s that bad. MSX computers also have scrolling issues. You’re totally way off about the games being terrible otherwise though.
As far as the NES being able to deliver hardware scrolling for cheaper, well, it just didn’t have the same requirements. Japanese computers needed to be able to display kanji, which meant twice the horizontal resolution of similar English computers (640x200 instead of 320x200). They’re computers first, gaming was a secondary concern.
There’s lots of games for PC88 and PC98 that don’t require any scrolling at all, including the well-regarded Snatcher.