Why do I have to create an account?
So that when somebody finds one of your lists that they like, they can click on your user ID and see if they like all your stuff. Your account is the only thing that associates you with your content. That's it. You only need to create an ID and password. No marketing surveys. No intrusions.
Requiring registration for commentors reduces spam and keeps the level of discussion a bit more civil. A large portion of the abusive and/or problematic comments on most sites are left by anonymous users.