"driven by ideological goals"
If you define wanting to defend the ability of people to freely share as "ideological", then sure. But he is driven by extremely strong principles that he's unwilling to compromise on, as distinct from his being driven by slavish adherence to some doctrine, which is the suggestion that clearly comes through in your post.
I have never met Stallman and so cannot comment on the assertion that he's somehow like a crazy person. But this is irrelevant in any case. His ideas are relevant. Frankly, I couldn't care less whether or not Stallman is as crazy as Hunter S. Thompson on a binge or is the epitome of 'normal'--his arguments are either sound or not.
His views on copyright are clearly consistent with his views on software. While the addition of anti-DRM principles to the GPL 3 is debatable and perhaps ill-advised, it's also clear that patents and DRM could be used to circumvent the intent of the GPL while legally following it, and Stallman is attempting to address this.
Whether or not the views on any of this are 'mainstream' is also fairly irrelevant, and further is rather difficult to prove. The 'mainstream' appears simply uninterested in the subject, rather than actively supporting the status quo or the move towards ever-greater restrictions. Stallman would definitely support the move back towards the original constitutional limited copyrights, so I'm not sure why you contrast this view with his view. Yes, he wants the freedom for anyone to share any published work, and yes, this may effectively mean 'distribution', but it's certainly not easy to find a reasonable balance between the original conception of copyright, the technological advances that have radically altered the landscape, and the fact that limiting distribution effectively means limiting sharing (and handing all kinds of power to the big copyright holders). Stallman's ideas in reaction to those tensions are consistent with his views, and that they are perceived as 'radical' indicates how ridiculous the status quo is and the degree to which the parties with vested interests in strong anti-sharing mesaures have managed to control discourse on the subject.
Stallman may in fact be wrong about DRM and the GPL (although I'm not convinced of this) and wrong in his push for absolute right of distribution of copyrighted works (I'm not convinced of this either), but in neither area has he abandoned or altered his principles, nor is either argument inconsistent with his previous expressions of those principles. Accordingly, I have no idea where your claims that he's "lost his sense of perspective and his grasp on reality" are coming from--unless you have always disagreed with the principles he's espoused and are using ad hominem attacks to make them seem untenable due to the fact that they're promoted by 'a crazy person'.
