This particular statement posted is actually two separate statements that are being conflated despite not being related:
People who collect many newspapers or cats are called "nuts" by "us"
People who have a lot of money impoverish the nation, but "we" treat them as role models and put them on the cover of Fortune
The verbal slight of hand here is that newspapers or cats are comparable to money. The basic reason that "we" find the latter to be desirable is that money is more useful than cats or newspapers.
Even someone who loves cats will eventually find that for each additional cat they purchase or acquire their desire to have an additional cat diminishes. This is called marginal utility.
Someone who collects newspapers actually may have a pathological problem with their collection. Newspapers are generally only useful once, or shortly after they were printed. The have reducing utility for each passing they they are collected and take up time and space to store appropriately. In rare cases, some newspapers and cats can hold value to others. However, typically they are not exchangeable and so they only provide utility to those who have some kind of attachment to them.
Cats and newspapers are also not easily fungible. With currency, you can have smaller units. So you could purchase an item for 10 cents with a dollar and still keep the portion that you did not spend. This is very difficult if you are trying to exchange for goods or services with a cat. Similarly, newspapers are not easily convertible. While they may have a high utility to someone, they do not have much utility to other people.
Money, on the other hand, is useful because, typically, it is something that is both fungible and convertible.
According to the APA:
Being careful about how you spend your money can earn you a reputation for being frugal, but when the penny-pinching goes too far and money is essentially hoarded, that can be a symptom of obsessive compulsive personality disorder.
Frugality is a symptom of obsessive compulsive personality disorder (OCPD) when a person "adopts a miserly spending style toward both self and others,...
“People with OCPD are people who are very preoccupied with details, making lists, workaholic, very frugal. People with OCPD do not have intrusive thoughts, so they don’t worry about their symptoms. To them, they wonder, why is everyone else not as organized and as neat as I am?”
People with OCPD might be so frugal that they'd go to a food pantry or skimp on essentials, even if they had enough money for all they need.
During a recession or economic hard times, when tight budgeting is widely admired, it can be tough to know if you’re overdoing it. The most important sign that you’re going too far, he says, is when your frugality negatively affects relationships or the quality of your life because you can’t spend time or money on fun or relaxation.
Or put another way, pathological hoarding is only the lack of action to spend money, not the collection of it.
Further, people who have a lot of wealth generally do not have a lot of cash, per se. The people on the cover of Fortune, as the quote mentions, have large holdings of companies. And what cash they do have, the bank turns around and invests the money themselves, such that money is rarely sitting in a vault somewhere being hoarded.
When they invest their wealth, their value is derived from their holdings. When we say someone is worth $x million/billion dollars we are saying how much money you could get by selling all of their ownership and converting it to cash by selling it. Ownership of a company is less convertible than money, though still more convertible than cats. If you sell several million shares of a company, the price will probably go down because of the additional quantity supplied. When the price goes down, the value of the company goes down. This means there is less money for the company to spend on increasing supply (often by hiring workers), diversifying their products, or acquiring better facilities.
So even when someone has a lot of wealth, they probably are spending the money (not hoarding it) but they are spending it in ways that also have high marginal value for themselves. People who have pathological hoarding collect things with negative marginal value, like cats.
Tl;dr, the FaceBook response should probably be: "Because money is more useful than cats."