In Australia the interest rates are about 3%-4%, some banks give you 5% as long as you deposit $200 a month and don't withdraw. Sure, inflation + tax takes most of it away, but you're still becoming wealthier. What's different in the US?
It's actually much worse than that when real inflation numbers are used.
The US economy is built upon a principle of credit(debt) greater than previous credit(debt). As a result borrowing is "encouraged" and saving is "discouraged". If you look at the sum of federal monetary policy you will find it clearly supports this blatantly non-capitalist principle. How can you have capitalism without capital?