Uncle_Sheogorath I actually do think this is fair.
If you looked at 2000 episodes and thought hey that's fine. Imma read it anyway, then you should be okay with reading 600 chapters.
Like think about it this way. People used to have to go and pay to read a novel. (Yeah! I know! pay to read a novel... crazy, right.) and when they did they bought the whole book not just part of it, didn't they.
The author didn't ever walk up to them and say, hey, here you go, here are the first 40 pages of this novel for you to sample, How about this, I'm going to tear them out and you can have them before you make up your mind and then I will give you the rest so that way I don't inconvenience you with all the rest of my hard work.
No, you took a risk and you bought a 300, or a 600, or even a 800 page book, and you took it home to read it. If you didn't like it after the first bit of it, And they left a review after reading that book and they read more than one paragraph or a page, because otherwise it was a waste of their money, and effort to go out and buy it.
Now did you waste your time and money on it if you don't like it. Yes.
But is that the authors problem.
Nope. Because likes and dislikes are subjective.
So I do not think that asking someone to invest 600 chapters worth of their time is too much if you already looked at 2000 chapters and thought I'm going to read that long ass story even though, JEEZ THAT'S REALLY LONG. Because you can't complain about the length you had to invest in the story to see if you liked where it was going. You knew it would be long and drawn out process to get through the story line in the first place. Any book with that many chapters has filler episodes and if you didn't want to invest the time then don't click on a 2000 chapter book.
But yeah your point would be valid, If I had said I wish webnovel would require readers to read 90% or the whole 100% of the book before reviewing. Then yeah, that seems unfair to me and you would have a valid point.