I believe that if some one that you can about is completely out of control and will not listen to any sensible reason or logic then sometimes tough love is the only way to help them, I think whatever you do needs to be smart and logical and not done out of anger though.
Children that are being raised need boundaries, and these can be tough love at times. Children need boundaries to learn rules and respect for others. While tough love might be tougher on a parent than on the child, children often do want it because it helps them grow and learn.
There are times as a parent, or as a spouse, or even a friend, when the only option you have is tough love. There are situations when you are being taken advantage of and the choice you have to make is to stand up and make a stand. Sometimes you have to choose the painful option in life and then rebuild later.
I definitely think that tough love is necessary in some situations. Sometimes, parents are too unwilling to teach their kids how to properly behave or conduct themselves in some situations. I think that it is important that people realize that spanking your kids are important to teach them a lesson.