US-based AAA MMORPGs have development budgets in the $X00 million range, and only end up profitable if they're World of Warcraft or launched before 2004. They take, minimally, three years to launch. The primary customer acquisition method is a nationwide media buy which costs as much as the development costs do, and if you don't totally saturate the retail channel and then sell all your boxes, you lose.
By comparison, you can launch a social game for five/six figures in two months, your primary acquisition method will be virality backed up by cross-promotions and FB ads, if it doesn't work you shoot it in the head and do another one, and if it does work you double-down on development and quintuple-down on advertising and then print money hats.
League of Legends had budget which was 10x less , and it is profitable , launched 2009/2010 but I agree it is hard to make good hit MMOORG.
Got sold for cca. 500Mil to Tencent years or so ago , so yes you can make money but it is not easy
League of Legends and the other MOBA games are a very different model from AAA MMORPG development. (I'd call it a ridiculously superior model if I had investors who had staked me with $X0 million and told me make a video game, but I sincerely pray that I never offend anyone enough to have them sentence me to that.)
In app development terms it is akin to having to say hit #1 on the app store and hold it for months to get a decent return.
I think Age Of Conan was an interesting case, launched with big publicity and was quiet good. Things outside the introductory areas though weren't fully fleshed out and there were some big bugs. In the first couple of months they lost most of the user base, one you start a decline in an MMO network effects take hold.
They have put an extraordinary amount of work into the game since this point, building a great game, and had success with the free to play model. Still though, the biggest impact on where they are now was these first few weeks.
By comparison, you can launch a social game for five/six figures in two months, your primary acquisition method will be virality backed up by cross-promotions and FB ads, if it doesn't work you shoot it in the head and do another one, and if it does work you double-down on development and quintuple-down on advertising and then print money hats.