It's awful in the sense that it has a strong, edgy, 'Fuck the world!' theme. I don't know about you, but that is content that really only appeals to edgy teens or even adults, probably why it has a 7.5 rating. If it got rid of that and had proper emotional storytelling, then it would work a whole lot better. Maybe this author is new at this, or maybe they really like this kind of content, so I understand.
Also, it should be tagged if it really is a harem like in Novel Updates. Novel Updates is usually right.