It's hard to battle M$, especially when M$ licence agreements specify that no no M$ OS must be loaded by M$ bootloader, and that every M$ OS must boot through M$ bootloader...
That prevented Hitashi and NEC to release dual OS PCs (BeOS + Windows) as they intended to.
BeOS is an OS made right, and I've yet to see an OS coming close to it, and the last version of the OS is already 2 years old...
The Personnal Edition was meant to get some market (more BeOS installed, more market for BeOS devs), but it couldn't contain licensed code which costed Be, inc. money (hey it's free, they don't pay for you), so the pro was released.
It's easy to install the PE on its own partition/disk.