There are probably a lot of aspects that are at work here.
We've been seeing activity, basically on every classic server, not just zombie, decrease in previous, and most likely in the preceding months.
And in fact, there are probably so many reasons why that this is the case, that we probably can't think of them, or even discuss those topics anyways.
Honestly, how hold is Minecraft anyways?: It has to have been going on for at least 3 to 4 years now. Minecraft was still relevantly new back in 2011 and 2010, and as people were still skeptical about buying the game, Classic was always a nice choice in trying out Minecraft before actually purchasing either the Alpha, Beta, or now, to an extent, premium.
Even what Raxo said, Mojang's attempts to slow down traffic to classic servers, and their increased push for players to join into premium just go to show that Minecraft has shifted in a new direction, and that players most likely aren't going to waste much time dabbling in a lesser version of a game; especially one that the main company barely supports.
Now; despite my thoughts and belief that this idea is absolute bollocks, it is a strong possible reason, though I do feel there are a lot of points against this.
I don't consider the wiping of stats to be that much of a case of complaint honestly in terms of the server's decrease in activity. Obviously this is biased, but seriously, look at it; you shouldn't be playing on the server just because you want to continue playing just for the stats, but you should be here for the fun and the community, and not the silly, fake statistics; though they are a very, very nice goal to look forward to and attempt to gain.
But going on that fact: You should be here for the fun and the community.
What was it that
Hahaha00000 said on that the server has just a bit of a less friendly atmosphere?
Well, really WHO are playing on the server now anyways?
In my opinion, I believe there are a number of factors to this.
From what I have seen, the majority of our current playerbase are either Operators who are playing (which tend to be many), as well as a large number of trusted.
We seem to have an over-saturation of staff on our server at the moment, and as these Operators / Trusted tend to be friends and apart of this group, many of the newer players (Though of course, many are just as likely to be terrible trolls that we don't especially want to join the server) can be turned off by this closeness, and feel left out.
I am not entirely certain where this idea can go, or what I was believing would come out of stating this, but I do feel this saturation of staff has an effect on what the server is becoming.
I agree with the idea that our server, like Lava did, needs more variety again. The same old Hide and Seek formula seems to be getting stale recently, and with how most maps lately are either overplayed to the point of becoming sick of them, or a variety of not as up-to-par maps being submitted into the rotation, there is a problem with this.
Although Powerpill and Hardcore have normally, and always been mainly used in small doses and in moderation, we have, at least in my experience, barely have seen these in use, which is a shame.
Powerpill and Hardcore pose unique challenges that can really spice up gameplay greatly.
If possible, it would be extremely nice if we can have automated times when Powerpill or Hardcore Mode are set off, and if possible, there can be just a new whole series of maps created just for the purpose for these styles of gameplay that is possessed.
And honestly, 10 second panics are terrible. I've seen tons of complaints from players who aren't used to them, and whenever they do occur, seeing the way our WoM traps are designed, most players tend to be slaughtered in seconds. It is an unfair, and honestly, extremely annoying thing. It should not be considered an alternative to adding variety to the server.
Anyways, I think JWB has a point, again, we do possibly need a new gamemode that does not include Powerpill or Hardcore.
WinX64
I don't know what engine / version you created this on (Like McForge.), and I know this doesn't entirely provide a different or unique experience that isn't already included in the normal Hide/Seek game-play style that is already incorporated into Zombies, but in any possible way your old Freeze-Tag Server can be somehow incorporated as like a small, more hectic version of the basic Zombie Survival formula? It was a solid piece of gameplay from what I, and the other testers experienced back when it was supposed to be for Epsilon.
I know this probably isn't the place for such a suggestion, and you probably need permission from some of the HC's for such an implementation, additionally it may not even work with the current engine that's running the Zombie server in the first place!...
But as the thread is basically on thoughts on the activity of the server, perhaps this is a relevant statement of you, and perhaps it may be a good addition, though it is just as likely that I do not know what I am talking about here and may just be a waste of time, but it is just a thought, and I would like your own thoughts based on that request / idea, if that is not too much to ask.