You are both absolutely right, and absolutely wrong.
This forum has a low post per member ratio, true. But there are enough people who play Zy-el on PhrozenKeep as it is. There are approximately 200+ people that hang out there who post in the Zy-el section of the board.
The problem is they don't allow the discussion of third-party servers. If they did, Kato would have easily allowed the promoting of it. And all the TCP/IP people would easily join Zy-el and play it. But he couldn't. And Sunny and Jebs had user ratios to worry about.
Also, there are three better, more active mods on the site that seem to get more traffic: Eastern Sun, SnEj and Median XL. Eastern Sun is basically D2 with a lot more, and it's well constructed in difficulty terms. SnEj is the Zy-el game but for 1.12 and runs on an OpenGL library that allows 1024x768 - but it's retarded to install and hardly ever works. Plus, Seltsamuel operates the site in German, making it harder to ask for help in proper english. Finally, MedianXL is like a completely different game - not a single ability was based off an original skill. It's all custom jobbed for the most part and can be hard as fuck.
However, the only things I offered to the Zy-el community are:
A) A gateway to cheat via Maphack and D2Loader, since the former you need to do special things to ensure it works and the latter because there is no active link to 1.09d's D2Loader.
B) How to start an untwinked Zy-el character. Enough people have that problem.