I have, on several occasions. I've been that upset person once, even.

I know lots of people who are dissatisfied because they're obviously far more valuable than a peer at the same level, and lots of people who are resented because of their parasitism at a higher-level job. (This is in the government system, where salaries are pretty transparent.)

And that's exactly how it should be. If you're far more valuable than a peer but are being paid the same or less, you should be dissatisfied. Ignorance may be bliss, but I'd rather know I'm getting shafted so I can either renegotiate or look for a better opportunity.

We do get pissed about people making more money for less work, but we get over it. The people in it until retirement (and their 80% pension) know they're sitting on too sweet a deal to care. Those that know they're temporary either acknowledge it's temporary (e.g. I'm leaving soon after I get my diploma) or couldn't get much of a better deal anyway. In other words, our complaint is less about our situation (cuz if we wanted different, we'd have gone off and gotten it) and more a critique on HR's assessment of value, like armchair quarterbacking for HR or something like that...