The main page having Disqus and no longer promoting us had a major impact on it.
It did, but also the Internet is not what it was 10 yeas ago. People can go to any number of places to discuss wrestling now, not just a web forum. You don't even have to leave your favorite social media platform to talk wrestling.
Furthermore, this forum software is a decade old. And it's not likely to get updated. There's no new features, there's no increased social aspects (which are the rage in the Internet world now). There's no ability to embed Tweets, video options are limited to whatever we can put in BBCode, etc.
In addition, don't underestimate the growth of the Internet itself. There are so many more things one can do on the Internet. For example, ten years ago Netflix had only just started online streaming video and that was only to the United States. It wouldn't be until 2010 (if my info is correct) that they expanded to an international market. Since 2009, YouTube's video uploads per day has increased 20 percent. Twitch didn't even exist (in its current form) until 2011. And those are just video services which have seen drastic increases in activity. There are so many more things to do on the Internet now that there weren't around in 2007.
Also, one needs to understand the changing nature of the wrestling business itself. Wrestling is increasingly moving to a model about which there is less focus on the casual fan and more focus on the dedicated fan. This follows the pattern of many media entities, where there is just SOOO much competition now for video audience (just think about how popular video sites like YouTube and Twitch have become) that pro wrestling is increasingly moving to the HBO model of service, where you depend on word of mouth to get new viewers and then you offer them something special to keep them. The WWE Network was a brilliant move by the WWE and shows they were ahead of the curve.
But what this means for forums is that there is simply a smaller pool of fans from which they can draw. As wrestling increasingly becomes esoteric, there's just going to be less people who seek out a way to discuss what they've seen. And then throw in our ancient software, the prevalence of social media, the increased opportunities for entertainment, the main page using Disqus and a host of other factors and it begins to come clear this was just the path these forums were likely to take.