You're right. But the problem with this approach is that those hard-coded paths will be different if the user chooses to install your product into a different directory. And using relative paths is dependent on the shortcut's working folder, which doesn't exist if you want to start the product at the command line.
The correct, Windows Installer way, is to have a "directory reference", [DirID] which gets resolved at install time into the actual installation path. We'll implement this in a future version of Advanced Installer.