@Fafuncho
yes it does, you may feel like it, but the comment section has a use,
that is just one use, the comments section has many uses and the one you like is being met now just not in the way you like. Sometimes I use it to get a feel for why people like a manga as you mention, but just as often if not more I read them for fun, to share with people who have a similar hobby, who find enjoyment in the same stuff I do. It's not hard to scan through the comments and spot the casual vs review style comments.
I'd be be curious to see what sites you say are thriving. I'm guessing it is likely a mix. Political, philosopical, ... these types of sites probably do thrive with or without a like or similar system, since the people are going for heated discussions. Hobby sites that I visit typically are to share the fun and a system like you want, to me, don't contribute to that. Yes it can to some degree be mitigated, but these guys have enough on their plates that I would rather they focus on the more major issues and improvements.
Honestly just a linear / threaded option would likely take care of most of your needs. You could easily scan for the start of a serious thread and then read it.
@calvitre said it better then me when I used the word timid. I hesitated to use the word timid since it didn't quite fit. In some cases it isn't just a timid person but some people come for enjoyment and if it becomes toxic will leave since it isn't fun. That's why I'm here, because it's fun. I would hate to see people like that go, people that are discussing just for the joy of reading manga.
it isnt there so that people chat about trivial things
Do you have a link that states the purpose? I'm curious, I wasn't here when they added the forums. Does anyone know why they did? I'm guessing it was to create a community, not just making "useful" comments. It seems like you would be better off with a simple review section with likes but no comments somewhat similar to MAL.