Often when people are trying to do something for the greater good they often make the mistake of focusing too much on that issue and can even make other issues related to it worse, I think that expression that the road to hell is paved with good intentions rings very true.
Good intentions are always a good thing. Sometimes good intentions, however, can end in bigger problems. Just because someone has positive intentions, doesn't mean their actions are going to turn out for the best. It's important for people to think about the big picture before taking action, rather than just approaching things from a positive place.
Yes, good intentions are sometimes the leading cause of worse problems, because people do not realize the problems that can come with some policies. For example, giving people cash and housing instead of working sometimes keeps people from being willing to find a job. People mean well, but there are sometimes unintended consequences.
It seems to be the exception rather than the rule that good intentions lead to bad problems. You will occasionally see this occurring, but good intentions can usually be realized in a way that promotes advantage. I would not say they have ever been the primary reasons for bad problems existing.
I do not believe that good intentions are sometimes the leading cause of worse problems. I think that good intentions can cause some problems to be worse, but they are not the leading reason for it. Good intentions are usually supported by careful thought. And when something has that factor, it can't always be a bad thing.