who should one be loyal to?

Yesterday, I resigned from my job, and am soon joining my new employer who's a competing company of my current client. While I was in the process of resigning, I got thinking about loyalties. Should I be loyal to my current employer or the new one? In the two years of my current job, I've striven to work for my brands and beat the hell out of the company I'm about to join in a few days. Once I'm with them, I'll work with the same passion for my team, but then the team will be different.
May be its just about where your salary is coming from. Who ever writes a bigger cheque, I work with them. How different am I then from Indian polititians who change parties by the day? Make promises to people from one party one day only to skip and move on a few days later. Its only about using the right platform to move a step higher on the corporate ladder. Which brand you work for doesn't really matter. What matters is whether the brand works for you.
But then, are employers any different? They will hire me till I can add to their kitty, and throw me out the moment they think I cannot do that. While I'm adding to their kitty, they don't really care about my personal kitty. I'm only a hole in their coffer which is draining valuable money.

Hmm. Basically, no one really cares for each other. We are only using one another to fulfill our own dreams. Its just about trying to be the bigger fish in the pond, and making sure you don't get eaten up.