It's not "all" on the manufacturers. Obviously, this will depend on device (coughiphonecough), but Verizon has almost full say on what apps are allowed or not allowed on the images these folks put onto their devices. The bloatware apps that are on your device are rarely if ever at the discretion of the manufacturer. The apps that are pre-loaded are often at the behest of Verizon and they make them UN-INSTALLABLE (there is no reason they should be a /system app). There is no reason I can't uninstall VZ Navigator on an Android device. Who actually uses VZ Navigator in lieu of Google Maps/Navigator?
Also, the reason I mentioned the UI elements is that if you consider the update/upgrade cycles they add to the process and then further VZ adds to the process
So you have:
1. Google releases update
2. Manufacturer updates AOSP to fit their core image
3. Manufacturer adds per device drivers/customizations
4. Manufacturer adds per carrier applications
5. Manufacturer submits image to carrier for 'approval'
6. Carrier does internal testing
7. Carrier does soak testing (to users signed up for soak)
8. Carrier releases update to phones
If you eliminate carrier control, you get rid of steps 4 - 8 and the manufacturer can just update the phone directly. Even then I'd prefer to eliminate step 2 and just use stock, but that's neither here nor there, I guess.
I'd put money on Apple being exempt from some of those steps or prioritized, which is completely unfair to us non Apple-devotees.
