This is intentional. I am open to changing it, but it's UX's call if this needs to change.
The reason why you don't get the license again, is that you don't have to agree to the license to *use* Ubuntu One, you only have to agree to make copies (for example, when installing). I think the bug is that you can actually not uninstall it, or that it can be started before the installer agrees to the license.
About the uninstaller being called:
This is intentional. I am open to changing it, but it's UX's call if this needs to change.
The reason why you don't get the license again, is that you don't have to agree to the license to *use* Ubuntu One, you only have to agree to make copies (for example, when installing). I think the bug is that you can actually not uninstall it, or that it can be started before the installer agrees to the license.