It's always easier to criticize someone else when u're not in their shoes. Honestly speaking, the focus of manager would be more on project and people management rather than just technical skills alone. Of course there would be some rotten apples, but I've known alot of managers who are technically strong with high EQ. My advice to u is that, look urself into the mirror before criticizing others. While u think a manager only delegates and sit in the office doing simple stuffs or relax, think again. things do not always appear as easy as it seems.

p/s: I'm not a manager, but i have spoken to a lot of managers and observed them. It's not difficult to observe and understand what a manager actually does in day to day work. looking at ur comments above, you did not sound like u have good relationship with ur managers