Now you know why, even if it is/was an excellent program, they never planned on someone uninstalling (and on Windows if you install NIS you may find yourself someday reinstalling the OS!).
Really good to get to know your system folders, and if there is a log of what got installed, to save it with the program.
I actually think there is a place for having a more 'official' programs center for seeing what was installed when, and to uninstall. Just that Norton has had this 'habit' for as long as I can remember with OS X.