correct me if i'm wrong, but "open source" doesnt mean every android device has r/w system folders, unlocked bootloaders, etc. i think people confuse the term.
open source means the source code is readily available for anyone to make their own device. cell phones are a new frontier for open source OS. it isnt fair to compare phones to computers. the manufacturers are simply trying to protect themselves. sure, maybe they are making mistakes, but this whole thing is rather new, and they are simply trying to protect their bottom line.
android source code is readily available, and anyone can make applications, and we can get apps from anywhere. that is what open source is all about.
do i want devices with unlocked bootloaders and superuser access? of course. but, the fact that a manufacturer can make a device with android and lock it down, and set it up however they want, is exactly what open source is all about.
if you all want devices that arent locked down, and come pre-rooted, then you should also be prepared to pay $500+, and not expect the carriers to support them nearly as much. if you brick the device, too bad. i would actually support this, but it's not good for the average phone user. i may not be completely happy with the way things are, but i can't say i dont understant it.