It's about the difference between the attitudes of a business owner who depends on customers for his livelihood and a government employee to whom more customers only mean more work for him but no direct benefit. He makes the same wage if one customer comes in or if one hundred customers come in.
In socialism, there is no incentive to do more work because you will not get an increased benefit form doing more. In capitalism, you can have your own business and, the more you do, the more you make.
As they used to say in Russia, "We pretend to work and they pretend to pay us."