Although I do agree that the first few chapters of this manga does feel boring compared to the first few chapters of Re:Life, I do not agree that it is a bad manga. In fact, although at times it feels boring and unrealistic, it still delivers a clear message.
What I think is the problem of this manga is the lack of a hook. What Re:Life does so well is that they hook the reader on the very first chapter with the introduction of the choice to become young again. Blue Hearts doesn't have that. The first arc does have some sort of hook, but it isn't as strong since sexual violence isn't as common as losing someone dear or regretting past mistakes.
Another problem is that sometimes it feels unrealistic or boring. Personally it wasn't unrealistic to me but I could certainly see why people would say it was unrealistic through the actions of the MCs. (not calling adults to solve situations, etc.)
Even with these downsides, I do see many upsides that come with it. The interactions is very interesting to read through especially with the main cast. In my opinion it was just as entertaining as the interactions in Re:Life.
Another upside is that the themes were more deep and intense compared to Re:Life. I do see it lacking originality but originality is pretty limited when you've covered up pretty much everything in Re:Life. Keep in mind most original ideas come from existing ideas mixed together and in my opinion Blue Heart does that well.
This is definitely not as good as Re:Life, but keep in mind that Re:Life hd a Sci-Fi twist, so I could understand the lack of a good hook. I can see the thought that was put into these themes and I really appreciate the author spreading awareness that these themes are more common than you thought.
The characters motives were also understandable, although still a bit unrealistic. I could definitely see myself in that situation if I was put in their shoes.
Overall I think this does not deserve to be axed, and I don't think it should be viewed as a disappointment. Blue Hearts is a good story that is lacking the flair of Re:Life, but is a good story nonetheless.
tl:dr: It's worth the read if you're a fan of Re:Life, but does not pick up until 10 chapters in. At first the characters would seem bland at first, but you will start cheering for them more once you get to know them through the story.