While it's easy for me to blame social media platforms namely the usual suspects Facebook, Twitter, Instagram, Youtube, Reddit, and etc. The truth is a lot of the sites that I frequent that do have message boards and have been around a long time they are now come in seemingly 2 kinds:
1) The boards are for the people who have been part of the site for years and they tend to be kind of protective to new people or in some cases down right hostile. The "keep off my lawn" type mentality.
2) The boards are so crowded that admins and mods have to be extra strict with to the point where even the smallest problem is dealt severely now granted these boards often have over a 1,000 registered members logged in most of the time and on sites like those stricter moderation tends to be the case with large boards to avoid major flame wars.
Even message boards now to have a Twitter account and/or a Facebook page just to survive. It also isn't helped that these sites are ran on banner ads and subscription fees to keep banner ads off the board and neither are as effective of just getting an ad blocker add-on for your browser. Those apps for posting on message boards on smart phones are annoying.
Major companies are turning away from message boards in favor of social media because they don't have to deal moderation Marvel, DC, Image, IDW, BioWare, Impact Wrestling, ROH Wrestling, and several companies closed their message boards and went to social media.
It is sad that my Conforums message board a board that I ran for over 15 years is gone, but I saved what I could and set it up here even though the X-WCW Archive wasn't what I planned for Outlaw Colony.