It's fine and healthy to be social at work. But I'm not sure if it's healthy to hang all of your life's needs on work. The bonds you form from work are usually temporary and conditional upon continuing to perform well at work. This can add a lot of pressure: you can lose your coworkers and your "friends" in one fell swoop.

The bonds I form outside of work are simply because we enjoy eachother's company. Or a shared hobby. Something that doesn't require me to be at the top of my performance. As long as I don't do something ridiculously inappropriate, they will still be my friends.