Plenty of things at play that could explain that, like other places to read or if they were reading here while more chapters than up to here were available, they just didn't take the time to stop and comment because they wanted to see what came after that even just a little bit faster, y'know? I often don't feel like commenting when there aren't already comments on a chapter.
Might be a blessing in disguise that this has so few comments on so many of its chapters, come to think of it. I seem to recall a constant stream of bitching and moaning about the age gap on the other site I had been reading this on originally. Also bitching and moaning about the track club friend, the guy working in the kitchen, the older female waitress, the younger track girl that admires Akira... If a thing or a person exist in this, the comments were way too often bitching and moaning about them, or about all the bitching and moaning haha.