I would say because the boards are pretty empty. The most guys come here when a link gets posted on reddit.
Also many posts or even answers are so short that it is not even worth talking about.
The boards are like a large dark space and sometimes someone says "hi" and then you hear another person also saying "hi" around 2 days later and then silence again.
The other problems is the deepth of the topics. You instantly realize that for most topics people haven't even thought about what they say.
And last but not least the splintering. You find multiple posts about the same topic when the topic is larger. There are like 10 posts about the NB3 incident and opnions and so on just on the first page. This just creates heavy bubbles for people here with their strong but often wrong opinions.
Overall boards are empty and useless most of the time with nearly nobody decent to talk to.
As an example take this post: https://boards.na.leagueoflegends.com/en/c/general-discussion/jMG8BLAE-so-riot-can-make-a-dota-chess-clone-in-less-than-half-a-year-but-at-the-same-time-they
The OP is not totally wrong with being a bit mad at all the bugs.
but Riot also has to make money for their employees and for Tencent (or they take over).
Fixing bugs is not always super easy and putting more people onto a single bug doesn't always help.
Complains about balancing when he himself has likely 0 idea about the state of the game and the current balancing
Calling it a dmg meta since S6-7 when we had a lot of good tanks in these years and people even calling it a tank meta at certain times. We also don't really have a dmg meta at all, we have a bruiser meta in competitive (top, mid, jungle).
Has no idea about clash. Yes, creating a ton of games at the same time is a problem for the server. Spacing it out over 30 minutes works but requires time and people would need to be present and many need to wait longer.
Talking about riot not listening to constructive feedback and using the boards for his example when the boards rearly hold any useful contructive stuff that is actually useable.
The guy is mostly just ranting and everybody in this post will likely go with him or leave it be. How would you deal with a smartass that has no idea but talks all big and gets other people in the same bubble into his boat? You don't. there is no way Riot could give him and the guys around him a good answer.
Another example: https://boards.na.leagueoflegends.com/en/c/general-discussion/GvgnUALH-the-ranked-system-isnt-as-accurate-at-measuring-player-skill-as-it-could-be
The guy talks as if he has any idea, but he doesn't.
A lot of the times you see that even challenger players have a hard time carrying their dead weight gold players on their team.
True, some struggle with a 70-90% WR. A hard struggle. And yes, sometimes there are unwinnable games, but that doesn't mean ranked doesn't work. Yes, it makes it less accurate, but there is no better way and his way of trying to evaluate player performance is impossible to do well.
I take the small and mostly unimportant inaccuracy over a system where you think you evaluate a players performance but you actually don't because it is not a 1v1 game and no lane is a 1v1 and especialyl not a 1v0 (which is the only way to isolate a single players performance).
So to think you can create a better system than all the games before just by doing something so obviously bad is a huge fuck up. Happens.
What would Riot get from answering? Telling him that he has no idea and coming out with all their numbers that nearly nobody reads on the board and the OP will in the end just ignore it all?
Even my answer here will most likely not get much attention. Too long too read.