You must be talking about the Fast Company link. Important to note that the number amount of money isn't what is important. What is important more than that number is the buying power and the social relations involved (the cost of freedom is rising). Inflation, differences in cost of living, rising taxes, or even what you like to do, all influence how high or how low that number will be.
Income satisfaction really depends on the individual, you don't have to cite any aggregate of other people's opinions on how happy they are with their lives and their incomes to know how happy you are with your own.
Some people don't mind spending life in prison but most people very much mind this. This is why public sentiment is so essential for determining what most people like or what most people want.
If you aren't happy with how much money you're making now then you're not happy! It's as simple as that. It would be more useful to look into why you or anyone else is unhappy, than to just say that since other people are unhappy, clearly you should be too.
Slaves often were not happy and would run away or die fighting for freedom. Is it much of a leap to figure out that if people are willing to risk their lives that maybe they really really want that freedom?
Money buys freedom. Without money you cannot afford a lawyer, you cannot afford to travel, you can barely afford to eat food and even if you do you cannot afford healthy food. For people who pursue happiness which requires freedom then yes there is a threshold amount of money which makes that pursuit possible.
Whilst the number in monetary terms is not the same for everybody it is a number and most people have one. If you don't then feel free to dedicate your life to charity, altruism, and asceticism. Nothing is wrong with asceticism but most people have material comforts whether it be an air conditioner in the hot summer or a favorite food.