>>283157991
The standard for that.
People can blame all kinds of reasons. The last arc dragging on, Ken throwing a temper tantrum to the proposed law, UQ holder, not getting a proper anime etc. But I think it's a collection of all of those things plus not having a lot of staying power.
You can apply it to most of his series really. Even Love Hina is mostly forgotten today. You'll be hard pressed to see its DNA in any modern romcom anymore.
>>283162853
This one and Ao no Exorcist were big back then. Yet no one cared about the manga ending or AnE getting a third season