Do you think that is because here there is so much more importance placed on shareholders over employees?
Company leaders should always put shareholders interests ahead of those of their employees, customers, and other stakeholders. They are required to buy law.
Fortunately, those interests usually align. You treat employees well because they perform better. You take care of your customers because they buy more from you. You take care of the community because it enhances your corporate reputation and makes people want to do business with you. In the end though, as a corporate officer, your fiduciary duty is to the people that own the company. You don't have the right to give away the shareholder's money. It belongs to them.
No one company is big enough to save the economy on their own. If a company retains staff beyond what it needs, they lose money (or make less than they otherwise would). Eventually, they go out of business and all of their employees lose out.
Employee turnover is expensive. It is costly to acquire, train, and retain employees. For that reason, companies don't like to cut staff more than necessary.
Europe's model is very different from the US. In Europe, it is much harder to cut staff. That helps employees in downturns, but it hurts them at other times. Because they have much lower labor flexibility, companies are less willing to hire employees. There is a lot more risk to hiring an employee if you can't terminate him later. That's one reason why Europe's unemployment rates are usually much higher than they are in the US.
Labor, like everything else, is subject to the laws of supply and demand. During an ecomonic downturn, the demand for labor shrinks. Until labor prices (mostly wages) decline, that usually means that there is an oversupply (people unable to find work). If you change the rules to prevent companies from cutting workers, you'll get two problems - companies will be afraid to hire new workers and companies will pay their existing workers less. On the plus side, having more workers looking for work will mean that companies can pay lower wages, which means that they'll be more profitable, which means that they'll grown and hire more workers, which means that wages will get pushed up. It's a circle of life thing.