there is a difference between what people claim is "tough love" and what is actually tough love. some folks will erroneously use the term to excuse abuse or bullying, but I promise that there is an actually effective and proper way of being loving and being tough on somebody out of love for them.
true Tough Love involves doing what is in the best interest of somebody for their happiness, health, and safety, even if it means that you aren't sugar-coating it. it means telling painful truths instead of comforting lies. it means disciplining your children instead of rewarding destructive behavior. it means offering constructive criticism instead of reinforcing incompetency.
an example of tough love would be to tell your child that their pet fish died because he wasn;t taken care of, instead of buying him a new one and pretending it's the same fish. it's a bit of a cliche example, but there it is.
another example would be the following: your kid has decided to join band. you tell him that you are willing to pay for the events, and instruments, and extra music lessons after school, but only if he promises he is dedicated to it and won't give up. he gives you his word.
then, a few weeks go by, and he's had enough. he feels like he isn't as good as the other kids in band, and he hasn't made any friends, and he wants to quit. you ask him if he's sure, and he confirms that is what he wants to do.
the tough love approach would be to tell him that he's breaking his promise. and if he really wants to do that, it's fine. but he'll have to pay for his next extracurricular activity himself.
or, alternatively, the tough love approach would be to have him make the promise to himself instead of to you. and when he says he wants to quit, you ask him if he's sure but don't try to change his mind. when he asks if you are dissapointed in him, you simply tell him "why should I be? you didn't let me down -- you let yourself down."
I find tough love to be appropriate at certain times. you need to make careful judgements about when it's best to use tough love and when it's best to use the light touch. sometimes you can even blend them together. you don't use one tool for every job.