Wow, you have really solidified for me the main reason for periodic, formal reviews with the employee. Yes, managers should give feedback, ideally throughout the year. I have been fortunate to have pretty good managers throughout my career, but it sounds like just the opposite is the norm.

"Neither of these need involve the employee, however."
If I had a poor manager, and that manager could submit my review to HR or management or whatever entity controls career progress and raises without my input, that would be truly scary to me! The formal review process serves to protect the employee by allowing him or her to have insight into what the manager is putting in your record and giving you a chance to discuss it before signing off. Now I realize it may be rare that you can change what is said about you, but at least you know if your manager is feeding lies to those above her and might have more incentive to change jobs.