What kind of business model would a game like this have, if it's so great?! Anything that needs frequent dev intervention (anything where you can change the world) needs paid staff, and ads won't cover it.
In general either you needs lots of players (so you can sell adspace and get occasional folks to buy stuff) and offset the costs of development and hardware, or you need FEW players and 'simple' enough development that it's a labor of love with admins occasionally coming from the playerbase.
IMO the latter is better, and it just might be muds that you're after. Graphically weaker, but gameplay is deeper as long as you stay away from the hordes of trashy ones. I recommend Aardwolf if you're a fan of grinding for 15 minutes, half an hour at a time, and RetroMUD if you like working in parties of 2-8 people with very distinct tasks more than you like soloing.
(Since I really feel like pimping RetroMUD right now-- Levelling is 'newbie levels' until level 10 or so, which are essentially handed to you on a plate; through 20 they're mostly easy, then they ramp up pretty hard. Once you're in the meat of the game though, there's enough varied places to last you a long time, like years. It's possible to powerlevel, but it's just as fun to go through it slower.
Class balance is kind of fun...being a party mud it's less 'A is evenly matched with B' and more 'C really wants A, B and D in his party almost equally'. Somehow there's fresh spins on the healing and buffing classes, and of course the sheer number of classes is mind-numbing. Some people whine about the balance, but it's generally good natured... the 'hand' class, spiritually-aligned thieves is kind of nerfed with bugs right now though.
And there is an economy with plenty of gold-sinks in meaningful housing and equipment generally taken from monsters...It's all 100% drop rates, but many kills are challenging and uncommon enough that it's just not easy to find stuff! The only thing is it's not a PK mud.)