Loving a job - Hating a job

"Do what you love to do!" Is this sage advice or the setting up of a foolish expectation? Do musicians really love the business of music? Do artists really love the search for or retention of a studio? Do politicians love votes and fundraising? I am looking for opions and thoughts about what elements are really important to turning a job into a healthy career choice. What is it about a job that contributes to your health as a citizen or a family member? If no job is perfect, where is the tipping point between a healthy or unhealthy career choice and who is responsible for monitoring it?