Allegiance to your company is not necessarily a bad thing. For example, one of my guys got a better offer six or eight months ago and I couldn't match it so he left. About four months later I got paperwork in the mail from the office of unemployment telling me that he had filed a claim and wanting to know why he left my employ. Apparently the company that he had signed on with did not have all the local work they claimed and he spent a lot of days at home not getting paid at all. He called me a few weeks later trying to get his job back and I declined.
There are some cases where it can be true. I've been in the corporate world for a while now and I stay firm with no allegiance. This is mostly because I've been used and abused by the companies I worked for.
The very first company I worked for 8 years tried to frame for fraud. They laid me off, because I refused and told them what they were trying to do was illegal.