But let's go up here: " to not have a heart to do something" , it means you couldn't do it because it was really, really wrong or really, really bad and you know it's bad.

但是让我们往上说：“不想做某事” ，意思是你做不到，因为它真的、真的错了， 或者真的、真的很糟糕， 你知道它很糟糕。