I can only speak for myself, so, here is my reason for being here, and what keeps me here. Mind you, I am probably in the top tear as far as age (not speaking of mentality obviously) goes for this forum.
I remember visiting this sight when I was beginning to play Diablo 2 back when it was later in patch 1.09, this sight was one of, if the the most current and updated. If their was a question, many members would help one another here.
After trying to find a better sight, I finally joined, then 2 days later BF went down for god knows how long. Just out of curiousity one day, I ventured back here, and low and behold, you were up and running, but at that time I was not playing so what was the pont of me signing up again.
Finally, I began to play D2 again and signed up to this wonderful sight. At the time of early 1.10 D2 you all here were current and still very helpful to me, and I have learned alot for many of you.
The problem now, is that nothing is current, and up to date. You complain that no one is joining here. Why would they join when their are so many other forums that have proper guides listed for 1.11? This is one of the biggest problems that I see. Their is no reason for a new person to join, and stay. Not only this, but a good majority (not all) of the posts, and threads are call outs, and 10 year old humor.
If you want to gain more members, give them a reason to join some way shape or form. I can't speak for anyone else, or for certain sections of Battleforums, but, I do know that the Diablo section needs some serious updating.
The reason for me being here still, is, because I see potential in this sight, I wish it could be like it was before the shutdown. Yes as mentioned age has a factor in many people coming and going from here, (hell, the only time I'm on here is when I can't sleep, or, need advice on a build) but, if their was a large enough group of stedy posters on here that wouldn't even be a real issue, because their would always be something new to read that was worth reading that is.
Some of the rules that are in place are rather pointless, of downright not enforced. For instance, what is the point of banning someone for a period of time, when they can just come back and do the same thing over and over again? Where is the logic in that? Is this the type of people that you want representing this forum? Second, if a mod doesn't want the job, or, doesn't do the job, find someone that does. Why have someone in charge of keeping order, that does not do that, or causes problems in the first place.
From a objective point of view,
look at this and see how many pointless threads their are, I garentee, at least 1 will be on that first page. If someone sees this, they might not join due to these types of things, or some might join seeing that can do the same thing and have fun flaming, calling out other members, ect.
Basically, if you want more members to join, think what you would want to keep you here and, what you don't want to see, then make the proper ajustments. If this is unclear, make a poll for new members to find out why they are joining. This could show what areas to concentrate on more, or even what is more popular then others.
Once again, this is from my own point of view, since I can not speak for anyone else, but, it is rather annoying seeing threads like these pop of week after week, with little or no change for the better. I understand, it is very time consuming, and alot easier said then done, but rahter then constantly figuring out what went wrong, overcome and make things better.