"The author has tried really hard with this" ... First of all, I find funny people here taking the criticism of a mediocre story as a personal attack on the author. Every art, work that is put out there for consumption is subject to review, criticism and evaluations so both praise and 'trashing down' are valid and expected consequences for artists and their work. If nobody could criticize a work then it would make no sense to award quality. If something is bad, mediocre, flat or has flaws, it's not only expected to be pointed out but actually valued by any artist who values improvement.
Second of all, 'The author has tried really hard" is an empty assumption. One can also assume that the author is more interested in keeping a popular story going that is providing her coins by the paying readers and not so much worried about the quality of the story. Seeing that this story has so many loose ends, has added fanservice while sacrificing both MCs development, I'd think the author is not even trying anymore, just adding stuff up. Calling somebody's work crap is totally valid if this is the opinion of the reader. No artist is entitled to praise just because the piece exists. A work should be judged by its final merit, not merely by taking space or the amount of work it took. Imagine if you took the whole day painting the Mona Lisa with crayons and put all your hard work on it and the result was the expected crap. Although your hard work is commendable, it would not make up in any way for the mediocrity of the final result.
Last but not least --- this kind of comments is making the rounds around here. It has the purpose to shame the readers who are criticizing a story with the idea that they are disrespecting or being ungrateful to the author. This is such a misguided argument not only for the points above but mainly because the comments in here are not directed at the author. This is a site providing illegal content of their work. It's amazing how every person who came here to proclaim criticism is some kind of offense to the author fail to see the irony that, if they truly, honestly cared for the author's work so much, the best and right thing to do is not to be patronizing sites like this. The author is surely, 100% more offended by you reading her work for free than any comment made by a reader that doesn't pay to read her stuff.
Reading people's comments is even more interesting than the story itself!! this story is complete crap!!! Siwon is bitch slapping literally every reader!!