People make trade-offs, in some cases the perceived cost of making less money is: * Later retirement * Longer commute * Smaller house * Lower quality of life for the kids (no/limited private school, extracurricular, etc) * Limited network (which can mean power) * Decreased prestige in society (yes, society still see money as prestige) * Lower quality vacation * Less 'mating' options * Ability to provide to extend family & friends * Exchanging a stable income
People are afraid of change, "what if the lower wage means losing my wife?" "what if I realize that my new job wasn't what I hyped it to be and I can't get back to what I used to do?" The more you have (money in this case), the more you stand to lose.