It's not like trade mentor is hard to get, nothing is stopping people from joining the "exclusive" club. And keep in mind that players are "novices" for 300+ hours of gameplay now. Most of the playerbase is already eligible. The reason it's not completely overrun isn't the exclusivity of the status, but the cap on participants that already exists.
Mentors join automatically on login if they've toggled /novicenetwork join, even if they don't care to participate, and still count against the cap.
Novices join automatically with the same option, once they've been invited, and it sets the channel to their default channel which is a pain.
My suggestion is to remove the invite system and mentor/novice requirements, but make it toggle OFF automatically and have players manually sign into it each time they login. That way only players who want to participate will join, so you don't have the current situation where it's hard capped at 100 mentors who joined automatically and aren't chatting, and 100+ novices who joined automatically but forgot the channel even exists and whose only interaction with it is to send mistells and macro spam.
I also suggested a reasonable player cap (not unlike what we have now) so it doesn't get chaotic.
And they should make a server-wide general chat too, so people stop using the network for exactly that. Give players an alternative, and novice network can refocus to its intended purpose of helping sprouts.
Both positive and negative experiences are remembered better than neutral ones. Negative ones are remembered the best. So in your experience you haven't had a negative experience but had a couple positive experiences, and remember those over the dozens of neutral ones.
