Going off of the comments for awhile now I feel like 1 of maybe...5 people that are still reading this manga and enjoying it haha
Internet comments are never, ever representative of actual reader enjoyment. People who are displeased with something are way more likely to seek someplace to bitch about it. This disproportionately skews online criticism toward the negative. Never use that as a barometer.
Makes sense yeah, I hope that's true.
So the couple's life story was just a bait and switch for another pining romance story. Sad times.
I think the main couple are the most important characters still, we're just having side characters like Shiho explored and their romances as well. Shiho is an important character for this arc, but these events have led to better communication between the main couple as well and them growing closer. So in my opinion it's fairly well rounded.