I wrote up a year-in-review that addresses at least part of the question. To sum up:
- Summer is particularly slow on CC.
- Participation has been falling for years as students have found other ways to learn about the college admissions process.
The first will pass as the next generation of students start thinking about college applications. The second is a serious concern that keeps me awake at nights. (Not every night, but some nights. 
) College Confidential started in the distant past when there wasn’t much information online. Today it’s overwhelming how much you can find. In a sense that’s a positive development. But it has meant that CC is no longer an essential part of the college application process.
CC has modernized the interface over the years. (If you want to see some previous iterations, the Wayback Machine is a great resource.) But at it’s core, CC is still an old-fashioned forum. Personally I think that’s wonderful, but it does mean we are burdened with the baggage of the medium. A lot of people, especially our target demographic, have learned to be skeptical of forums. We can work together to show that CC is different from that negative stereotype, but it’s a process that must be repeated year after year as a new class considers joining and participating.
To be transparent, my professional goal for the coming year is to encourage more people (especially students) to register and join in the conversation. But I don’t want to fall into a trap we stumbled on a couple years ago where driving registration gave visitors the impression we were a paid site and hurt other important metrics.
I can’t do this alone! The best thing this community can do is continue to give amazing advice to students who do come and post on CC. The best tool we have is showing people outside of CC the great things that are happening here. For instance, if you look at our Instagram account, it frequently features forum posts. (Say that 3 times fast!) The plan is people will be drawn into the forums if they are interested in a topic we post about and once they are here discover even more interesting people and content.
So I do want to acknowledge that you have observed a problem, let you know we are aware of it and encourage everyone to think of how you can help. I’m optimistic about the future of CC because of the people who make up the community. We might need to change some of the ways we operate, but as long as we have a solid core of people who care about students and their education, I’m confident CC will find a way to help.