A part of why “just listen to your heart” doesn’t work is because people tend to get their minds mixed up with what their heart and soul is actually telling them.
The mind and the ego both for all its time in existence has tried to mimic the heart and the soul. The more that is found out about emotions and spirituality and things like that, the mind and ego will create a rigid pattern so that they can follow. This is because we still adhere to certainty, we still want a guide to present to us our vulnerabilities and moralities.
“Listening to your heart” only works when you get to know how your body works and what it communicates to you. If your body is rooted, it will naturally give rise to the heart’s song. The mind can go round and round in circles for years before ever touching a toe into the heart’s pond.