I understood what you were getting at, and yes it is for the reason that many plugins are not 64-bit compatible (yet).

The problem (for the third-party guys) was CS4 was 64-bit for PC only and not ready for 64-bit Mac users.
They had to wait for CS5 (which supports both 64-bit OS’s) to see what they had to work with for their recompiling.

As a side note: My personal opinion is that maybe around PS CS7, Adobe won’t even offer Photoshop in a 32-bit version.
They are already moving that way with both the new CS5 versions of After Effects and Premier Pro being only 64-bit.

 

Oh… and sorry to hear about your unsuccessful uninstall attempt.

Adobe products do such a deep system install, that when you mess around with them, they commit Hara-kiri.

 

chuck