You should probably educate yourself about modern F2P business models, in particular Wargaming's. World of Tanks is probably one of the best values in gaming if you like the core game.
They've been making good money off of their F2P titles, and now they're spending significant portions of it on revitalizing some otherwise dead franchises. Seems like something people should like them for, not fear.
People afraid of F2P might want to stop painting with such a broad brush when lumping every game into the same group as shit like Dungeon Keeper Online, you're missing out on some great games.
The flip side is, there's absolutely no reason for MoO to be F2P. Like, literally zero. Everyone enjoyed it as a single player game back then, and everyone would want to enjoy it as a single player game now. The best games were the ones which stretched across multiple afternoons, something that's not particularly conducive to shoehorned multiplayer modes, outside of a dedicated few who would be willing to make it work, not something that exactly makes bank.
Couple that with some somewhat
decent alternatives nowadays (GalCiv, Endless Space, etc. their own respective faults taken into consideration) fans of the original two games simply aren't going to jump ship to a newfangled model.
An F2P 4x might be succesful, but it won't scratch nearly the same itch, nor cater to largely the same crowd.