The nature of plug-in effects will always be subjective. I don't like the Concrete Limiter on program material at all, but it works really well for vocals and drums...for me. The PSP Audioware old school compressor emulation is wonderful if you like thick, but not if you like transparent. And so on.
The PC modules provide more tools for the toolbox. There are many instances where I like those modules better than anything else I have. There are other instances where plug-ins from competitors do the job better. So what? This shouldn't be news to anyone.
Bottom line
for me is the PC lets me get projects done faster. This would be meaningless if the plug-ins weren't good, but they are. I think it's really important not to get hung up on minutiae when the goal is to make music. When I DO want or need to get hung up on minutiae, I do A-B blind testing. It's amazing how few people can consistently pick something they feel is inferior or superior to something else. Many times the answer is that they're "different," not "better" or "worse."
My favorite line in speaker reviews is where the reviewer says that a particular speaker "revealed things I'd never heard before!" This is to be expected when no two speaker types have the exact same response curve and diffraction characteristics :)
If you don't like the PC, don't use it. If you like it, use it. If you like it sometimes, use it sometimes. Regardless, I would miss it very much if it went away because of the degradation this would cause to my workflow and completion time for projects.
As to whether being able to remove it should be an option, if it was trivial there would be no harm done but I suspect having this option would be just one more "moving part" to go wrong.