This is entirely untrue and extremely dangerous. It is very possible to love what you do for a living (I do). Some of us find "true freedom" in tricking people into paying us to do things we would gladly pay to be allowed to do.
Really? I must be an exception then. I love what I do and wouldn't want to stop doing it. That said, I can imagine myself in a few other jobs too, so it might be my attitude towards work that makes me happy.
I'm not talking of happiness in that context. You are never truly free if as long as you have to work to make a living.
Once you have financial independence you can do anything you want, take unlimited vacations, learn music, go hiking, ride a motorcycle all day, heck you can even code all day and work on interesting projects without the fear of getting fired, denied a raise or whatever.
Your statements carry with them the implicit assumption that "anything you want to do" and what you do to make a living aren't the same thing. For some they are.
Which is why everyone must strive to have a side income/early retirement plan because you need to experience true freedom to enjoy things in life.