Heh, how very true. I completed a round of interviews with a large, older, well-known company. The recruiter got me interested by saying they could match my current (well above market rates) salary. Through a total of 10 hours (over 4 days, including an on-site where they flew me out from the west coast to the gulf coast), the response was a solid "the team loves you, they love the work you've done, and they want you to do it here. Your salary requirement is no problem at all". When it came time for the actual offer, I got "Gosh, gee-whiz, so, apparently your asking salary is about $40k more than our most-senior team member for that group, we can't have such salary disparity among the team. Would you take a $40k pay-cut to come work for us?" I would've laughed, if I wasn't so annoyed. It came off like a classic bait-and-switch, but I could easily believe that an HR droid saw the deal when it was 80% of the way through the process and put the kibosh on it.
I have a friend who interviewed at iRobot a few years ago, the guy is brilliant, best coder i know by far. He may not be the most social (tough culture fit), but he can get work done. He went through the rounds, nailed the interviews, and eventually got an offer. If i'm remembering correctly it was about $5k more than he was currently making, but would require moving to Boston. If you factor in the cost of living (coming from Michigan) he would be losing money. He advised them that the offer wouldn't be worth it for him and they didn't even counter, just said, 'ok well thanks for inquiring'.
Companies also further constrain themselves by not allowing remote work.