Probably because most people don't compile their programs. They just wait for a built-up package
But seriously I truly appreciate the idea and effort, although it looks like it is going to be a one man that does the job. Everyone will be relying the person's free time and "pushing" him/her to "add my favorite filesystem". If the author made the code available (note it may not be such a good idea), other people can use his work and expand the functionality.
What about the PS3's file format? Because we can format to it using the XMB, shouldn't we be able to reverse engineer it and format external drives using it as well? I imagine this would require that someone creates a file manager for PC so that would could access the files (much like the Wii). But this would be awesome. I really don't want to muck around with my PS3s internal drive.