Why does the number of apps "optimized" not reflect removed apps? I've read the details on what optimizing does here: What kind of app optimizations do newer Android versions do at the first reboot?

And my question is slightly followup.

I run CM nightlies on my TF700T using TWRP to flash and erase the Dalvik cache each time. I understand the Optimizing process rebuilds the Dalvik cache, but it appears it tries to rebuild the cache using every single app I've ever installed, not just the ones currently installed. The total number of apps it optimizes never goes down, always up.

I presume this means there is a list somewhere in the system with all the apps this process must go through. Is there an app or utility that can update this list and justify it against a list of apps actually installed?

Or am I making incorrect assumptions and is this process also running through system apps that are not subject to user removal?
When Android optimizes apps it will optimize all apps, including system apps that you cannot see/remove (well, technically you can, but that's a different question).

If you just check the installed apps on your phone it will just show you the apps that YOU have manually installed and that is why the number is not the same.