I would argue that this is not true. If the CMs were paid more, maybe the first day or two you might see appreciation in the form of better service, but after that, people are creatures of routine, and the better CMs will be better, and grumpier ones will get grumpy again. It's more about who you hire, not what you pay them. You could pay me 100k to do a job I hate, and it will show!
People are creatures of routine. This means as well that people don't like change. Hence why there is outrage over the wanting of change to raise the minimum wage. People are scared of the potential changes that will come with it.
As for the comment of who you hire? Well, most places today have you apply online. If, and only if, your application can pass the pre-determined algorithms that "screen" applications or by chance there's actually a person that sits down and looks at those applications on the computer, you may then get a phone call from that grumpy manager who is stuck with a lousy crew because the hiring process weeded out all the "better" applicants.
Technology has helped us, but it has hindered us. I remember actually having to go to places of potential employment and do hand written applications, hand it to the manager, they review it (on the spot) and I got an answer immediately or at least an acknowledgement that I submitted something. Today, you apply online, hit submit and hope that when the hiring manager at a corporate office somewhere in a cubicle (think Mr. Incredible working for his insurance company) will actually not just "view, catalog, and send the generic 'we went with a better candidate' email".
I'm not saying you totally have to get rid of online applications, but there needs to be a better process at picking out people to interview. Many people today are getting rejected because they are "over qualified". Meaning, they have a college degree and the job only requires a GED at best. Why? The employment market has changed. Those students that went into college wanting to be teachers and such are graduating into a world where education has seen drastic cuts (especially in the fine arts ie music, pe, art) and they now have this wonderful piece of paper that states that they are "over qualified" for any job that is below an educator.
These "over qualified" people are now being held in limbo in the job market because they have too much education to be doing simple work, yet they can't find a job using the degree they earned. All the manager or computer sees on the online application (filters, etc) is that they graduated college, so it automatically cancels out their opportunity with the company, even though they might be the best worker that company could get.