How the hell is saving money a bad idea? You don't have to keep it in a bank, and investing your money just for the sake of it is a good way to lose it all especially if you don't know what you're doing.
There is the argument that people must go out and spend to get the economy going again.
That is the only reason that the government may not like people to save a lot. It definitely is not a bad idea for the common man.