I can try and shed a little more light to your premise...
First of all, I agree that the heart is the driving force...I share your opinion...
However, the world is in terrible shape---and is at the same time a perfect world.
Things just are what they are--it is humans who label it as good,bad,violent,peaceful,overcrowded,etc...
The earth was here before us and will be here after us---although we will generally trash it--maybe even destroy it...but then it will regenerate itself,heal itself and then pretty much....go on.
The problem with humans being driven by their hearts is that hearts get ...I guess the word is...clouded?...blinded?...
What I mean is that when you have a human being who is driven by his heart--but his heart has been clouded with illusions, desires, addictions, ambitions..then what is really leading that person is a false or clouded heart...like a blind person driving a car...sooner or later that person will do some damage...to himself and to others.
What causes this blindness...well it can be anything....
beliefs--you can be so sure of a belief that you assume it is fact...for example a religious zealot who believes that the bible is the ultimate truth and he will NEVER let anyone tell him different...then he goes around trying to convince others that they should also believe in EVERYTHING in the bible....
some believe a book or a testament or a dogma so much ---that they will kill for it---in the name of their god, their allah, their jesus....whatever
this kind of a driving heart has been polluted and will never see truth---because to see truth is to be open...what happens when someone makes a conclusion ...then every door is closed to any other truth he might find because he cannot go against what he has been convinced is the only truth...for example again--the bible...
there is a story about a young widower who lived with his 5 year old son...
the widower returned home one day to find his house burned down and his son lost.
Near the ruins of his house was the charred corpse of a child that he believed to be his son and he wept and wept.After the child's cremation he kept the ashes in a bag and carried them with him day and night.
But his son had not actually perished in the fire. He had been taken off by bandits, and one day he escaped and returned to his father's house.
The boy arrived at midnight,when his father was about to go to bed,still carrying the bag of ashes.
The son knocked at the door . ``Who are you?'' asked the father. ``I am your son.'' ``you are lying. My son died more than three months ago.''
The father persisted in his belief and would not open the door. In the end the child had to leave and the poor father lost his son forever.
When we believe something to be the absolute truth and cling to it---we cannot be open to new ideas. Even if TRUTH itself is knocking at our door.
There are people in the world with such strong beliefs who are running this world....yes it is their hearts that drive them everyday...
but these blinded hearts are doing more damage than actual evil people who are out to intentionally cause evil in the world.