i also think there is 2 different conversation going on here about windows uninstaller .and whos at fault for a fugged up registry or computer ....
So what could an uninstaller do?
Take a snapshot before and after installing a program? Doesn't help with per-user configuration files created later or authority. Possible false positives if any other process was running at install time (which would obviously be the case).
Monitor the process during install and log it? Again doesn't help with user configuration files.
Run continuously watching what all programs do? Apart from the overhead, how can a program tell if a file created by some application is left over crap or something beneficial? If you uninstall a ftp client you don't want to delete the things you downloaded with it.
What about dependancies? If some Visual C++ Redistributable was brought in by the installer should it be uninstalled or not?
Windows is unfairly maligned in this regard because of the scary "registry" word. I don't know about Linux but presumably the users configuration files in their home folder remain after a program is uninstalled. OSX in my experience is much worse than Windows when it comes to leaving stuff behind. Most programs make no effort at all to delete things from outside of the application bundle leaving all sorts of detritus behind that has to be cleaned manually (unless you trust a 3rd party cleaner to have a stab at it).
No, even if the registry was massively bloated there would be little impact on the performance of anything other than exhaustive searches. Registry Junk: A Windows Fact of Life - Mark's Blog - Site Home - TechNet Blogs
Doing at least something about it is certainly better than nothing ( normal windows uninstall), I have seen many MBs of data left on disks after such sloppy uninstalls. Revo and such are at least getting rid of most of the garbage and there's nothing stopping MS to do at least that much.
If the product is using windows installers and uninstallers wouldn't that mean the leftovers if any are caused by the windows uninstallers or would it still be the program itself?