It is somewhat more stable at the moment. Bitcoin is going up and up and up and at a certain moment people become afraid to hold it. That seems to be a dangerous situation to put the money in. Especially if you don't have it lying around. 

But more important than uses, is the fact that there is choice. Bitcoin is developed following an open source strategy. Forking a project means more people working on it. More people working on the code (even if it is a fork) means more safety, less chance the idea disappears and more new ideas are constructed.

PPCoin is a fork, which has some truly novel ideas in it. It doesn't matter it is better or not in the end. It matters that people can experiment with cryptocurrencies, so at the end bitcoin can evolve further. You can not do this kind of experimentation on bitcoins, but you can do it in a fresh fork.