The inspiration may have been all "crazy" but the implementation was still really neat, and it takes a lot of effort and skill to get to the point he did before his death. The thing about people who lose touch with reality is that their efforts to create or express something often make no sense to the rest of us. TempleOS, however, works. Terry create an OS from scratch, an entire new language (or variant of a language) in the form of HolyC, and not only does it all work together in a way that requires no disconnect from reality, it works well for his goals and philosophy.

The entire thing may be the result of a person suffering from schizoaffective disorder, but that person still held a great deal of skill to implement that idea and enough of a touch with the reality of computer hardware to make it happen.