He has not been hugely successful. He has failed outright at making users care about their software freedoms, which is why it's so easy to take them away from them. The users are the ones who care least about free software, mostly because they see every day how inferior it is to closed software. From the perspective of the average user, apple's stuff is far superior to the "free" stuff. This makes users interpret free in its worst meaning: free as in cheap, free as in low value.
And this is my real beef with stallman's brand of free. His freedom is a narrow-minded ideology, abstracted from what freedom means in the real world. In the real world the only freedom I care about is the freedom to spend my time the way I want. From that perspective, jobs did a lot to make me free, because the switch from linux to apple "freed" more of my time than it cost me.
It's also interesting to think that apple, in supporting webkit and web technology, helped make HTML5 happen, a movement that enables more user freedom than ever before. Even the ITMS, that bastion of evil, is just another web app selling DRM-free music.
I respect what stallman is trying to do, and strongly agree with it. I just think his tactics are dead-wrong.