People with that mentality, don't have 'loyalty'. People who have a job think that way. People who have a career are usually a little more strategic, and often strategy means long term gain, not short term profit. There are many in the world, that will stay where they are out of 'loyalty'. Not because they feel they owe something, but because it's the right place, it's the right thing. It's not all about the money... or at least it shouldn't be.
“Your work is going to fill a large part of your life, and the only way to be truly satisfied is to do what you believe is great work. And the only way to do great work is to love what you do.”
Steve Jobs
What do you think working at a retail Apple store is... or any retail store. It's a job, not a career. But even people with careers are constantly changing firms or companies because it's the best move for their career path, family situation, whatever. People stay put when they are in the palce they need to be at that time or they don't have the skills or initiative to look for something better or they are just complacent.