Thompson and Ritchie were among the first to realize that hardware and compiler technology had become good enough that an entire operating system could be written in C and by 1978 the whole environment had been successfully ported to several machines of different types.
If you're trying to achieve there will be roadblocks. I've had them everybody has had them. But obstacles don't have to stop you. If you run into a wall don't turn around and give up. Figure out how to climb it go through it or work around it.