With all of the (largely web/app-centric) development work that I have done, there are numerous concepts in OS development that baffle me. I don't claim to know what it takes to build an OS, but I know that it is beyond me.

Also, I wasn't questioning his skill as a programmer, I was questioning the undertaking that he is discussing. Any solo developer would struggle to create an OS (especially when they have a full time job to contend with), let alone someone that is going to have to learn a lot along the way. So my suggestion was to go ahead, but treat it as a learning experience rather than a deliverable product.