@Froshi Something that doesn't flaunt a pretense of depth when there is none. Don't get me wrong, the manga is fairly original and possibly above average in many regards. However it is clear that the author bit off more than he can chew.
The main issue is that all character interactions and events are way over the top. It is clear that the author wants to write compelling and thought provoking scenarios, and a deep and charismatic MC. And this is exactly the reason why it is so infuriating when he/she squanders the potential of the premise. The events are overdramatic and the character interactions artificial, the MC comes off as a caricature of some poser that wants to be perceived as "deep", his charisma shoved down the reader's throat by how the students perceive him, for no apparent reason- clearly not what was intended. I blame the author's lack of experience/talent/research.
I liked the beginning not specifically because it was dark, but rather because I thought that serious issues would be discussed in an equally serious manner in the manga. And as a bonus I expected that I would get to see a charismatic and intelligent MC, and not only be told that this is so. Needless to say I was fairly disappointed.
And yes, Oyasumi Punpun was a lot better in that regard. Not specifically because it was dark though, but rather because the author didn't resort to cheap tricks (for the most part) while developing the plot.