Because they didn't finish the port for the G4 Mac Mini because of obvious reasons; incompetent behaviour from all parties involved.
Instead of spending/wasting the time creating OS 4 for CyberstormPPC and BlizzardPPC and all it's possible hardware they should have spend it on the Mac Mini port which only has a few configurations.
The second hand base of these machines is much, much larger and would have helped as a bridge to an alternative hardware platform. This way a lot of interested developers would have been able to buy a fast and small and cheap machine.
A huge oppurtunity missed in my opinion.
