In fairness, everything every company every does is greed-driven.
Valve gives you free crap for years with some games. Is this because they aren't greedy? God no! It's because they think that this free crap will make you more likely to play this game longer, making other people more likely to buy it, and because they think the promise of free crap will make you pay for non-free crap, be it upgrades or other games, in the future.
Every single corporation in the world is driven by greed.
MMOs switch to F2P because of greed. They're getting smart about the greed, but still greed. Right now essentially anyone that's going to play this style of MMORPG is already playing it. You have to convince them to leave their game. If your game costs money they're not going to even try it. They're already paying, and not only are they already established in what they're paying for experience-wise (friends, loot, levels, etc.) but they are practicality-wise (auto-drafting payments every month.) Switching from that is a hassle, especially for something that might suck. And even if they were trying it so few are doing so that, relative to where they're already playing, it's a barren wasteland.
Make it F2P and suddenly there are no choices. They don't have to make a decision. They just download and put a few hours here instead of there. More people check it out. It's easier to convince clanmates to test it.
It's a heroin model - just let them get a taste and then they're hooked. If that taste costs money it's less likely to happen.
And it's still 100% greed. But, not to get all Gordon Gekko, but greed isn't necessarily bad. Damn near every accomplishment man has ever had has been out of hopes of riches, fame and power.