Perhaps I am naive and perhaps I don't know what I'm talking about but I do have 7 years with my current company. Three and a half of those as an intern and I was hired out of school at a very respectable wage. The reason I'm loyal is simple, the people I work for come from a culture where building a team is important. They hire people they've worked with in the past, knew from college, or referred to by current employees. The sense of community is strong. This is not true company wide since our division is the product of a massive buyout, but the culure has remained unchanged. I have expressed desire to retire with my company and my senior management and executives are excited by that possibility and have provided me with opportunities that I would not have recieved elsewhere.
Perhaps I just lucked out and found a company that was willing to invest and take risks on me and I offer my loyalty in return.