When you have multiple commands to run, chances are that only some of them require root privilege. Prefixing only those with `sudo` instead of executing all of them in a root shell allows you to reduce damage, should the "normal" commands are typed wrong or have bugs.
And I'm skeptical that having users type sudo a bunch of time when they add a PPA and install a program somehow results in greater awareness, but this is purely an opinion of mine.
The other big reason for using sudo is the ability to change policy wrt which users can be root without changing root password everytime, and that clearly is true.