Right now I am playing Rift, its kind of like World of Warcraft but its free and more fun (well I never bought into World of Warcraft so my experience with it is limited) anyway, I am really enjoying this game its a lot of fun, sure there is a pay shop and there are people who have more of an advantage then myself because currently I am not buying into the game or just starting out.
The reason why these companies can offer free game play is because of the people that pay into the game while the rest of us that don't get almost the same game-play experience which is ok. Not everything in life is equal, people keep complaining about pay 2 win, well if it weren't for these people paying to win as you all call it, then you would not see any quality free games especially not with regular updates. People are motivated in life by some incentive whether it be a girl/guy you just met or have been with for a long time, a new job, or just the pleasure of doing good toward your fellow (wo/man). The point is people need some form of satisfaction, whether it be monetary or otherwise to keep them motivated and moving forward.
TLDR
If
@Sir Knighter did not make money from his project then with his limited skills as a developer he would not be able to host or produce a well made game, built and paid for by you and his supporters. This ideal applies to all well made and regularly update projects, not just ot servers.
~Codex