ability to put your boss to the blamed and avoid his retaliating.:) My former manager had made so many mistakes that I'd fought him with, but eventually we the team members had to pay for them, and he was even promoted.
BTW, I almost missed your reply for my post. Thinking of your analysis now, and maybe someday I'll take action. The company I work with is a dominating one in IT industry, which explains why my pay would be doubled if I went out (I chose an internal transfer instead). I've also had a title of "Principle Engineer" for many years, but never asked for a promotion myself (all my promotions happened automatically). Perhaps wasn't dare to take more responsibilities. I'm kind of in retirement mode now (or want to be), it's just when thinking about "that's it for my career" that makes me uneasy...