But the only reason a business hires employees is to make more money. We are not employed out of charity. Can we complain that greed compels them to fire us when it also compels them to hire us in the first place?

Also, you are assuming the only one being rewarded by layoffs are executives. As someone dutifully putting away money for retirement in a 401k, I am the primary beneficiary of such layoffs in their stock prices(assuming the company is publicly traded). Should I feel guilty that my greed has caused layoffs?