More intelligence and the ability to solve problems is always a good thing! I guess the only downside that I could see (apart from the one that you point out) is that inventions and tools and advances are just tools... the end results can be used for good or bad ends depending on the user, so it is possible to create a solution for one problem, only for it to be used in a different way to create other problems.... (for example, nuclear power or nuclear weapons).