The mod has promised me something they haven't delivered- I have a right to complain.
You may have a right to complain if you are promised something that you do not receive, but do keep in mind that the moderators are sacrificing significantly greater amounts of time for nothing more than the sense of accomplishment, the appreciation of their peers and, on occasion, sandwiches (BTW, still waiting for that Grilled Cheese Thlayli).
If that's a serious challenge, I'm willing to run one and do better- I'm a lousy mod objectively speaking, but even I can set myself long ETAs and keep to them.
How long, out of curiosity, and what is the setting of the NES? I'm interested.
Very rarely does the mod have to make much additional effort per player- that's only the case . Not to mention, the mod likely wants and expects players, or else they wouldn't have made the NES.
I can not speak for all mods, so their voices on this topic would be greatly appreciated, but in my case, I have detailed plans for the setting, and my NPCs have their own goals and schemes going on, which are almost invariably turned on their heads by the arrival of new players. I don't begrudge them that, I greatly appreciate an active player providing their own directions for a country, but the transition is a significant change. Beyond that, it takes significantly more time to closely follow someone's detailed and carefully-written orders than it does to work from the general plan you know that a given NPC possesses, so every additional player involved in an update will add to the time required to complete said update.
a- You shouldn't have started an NES at 15.
I started an NES at 14 before that NWAG, and I'd do it again younger if I could.

But the big deal is that I've changed and developed a lot as a person in the last 5 years, and that'll likely happen more in the next 5. If you don't start now, you'll never improve!
b- It depends whether or not one person requesting an update rightly leads to more peer pressure as it should.
I... don't think that I understand this sentence. However, I don't think it addresses the point that peer pressure is ultimately an unhealthy fuel for a NES.
4. What do you mean? I have experienced the multipier effect with additional players: more plans to interweave, more things to make rulings about, more stuff relying on interplayer relations. Each player increases complexity. After about 5-10, every additional player adds much more to the work load.
Precisely. It is hard to coordinate between a bunch of autonomous actors working in concert or conflict with each other.
5. I started my first played NES at 11. So?
If you can write, you can NES!
