You might need to reread the article title. It is a strange way to say: if you stay in a career that you hate, you will be unhappy. 

Most people cling to the status quo.  The law of inertia, Newton’s first law of motion, stemmed from the observation that things that are in motion tend to stay in motion and things that are not in motion tend to stay still.  

Given that you are not in motion, you might think the “alternative” move is shifting your career path. What if you flipped the switch and viewed yourself as in career motion?

Your alternative to motion would be staying. So, your alternative to moving to something you will or at least might like would be staying in something you know you don’t like. In other words, you would be choosing the “alternate path” even though you know it would lead to future unhappiness.  That, of course, would make no sense.

Staying at a job that you don’t like similarly makes no sense.