Depends on who you are asking because there are some people that will say it's good for currency as well, I mean it has been used as one back when Laszlo bought 2 pizzas right? I think it's a bit of both because Satoshi's aim was to create a currency that will eliminate the middle man which is the banks.
The presence of bitcoin is a better thing than a bank transaction system, complex global transactions are easy to run with bitcoin, whereas if a bank is a bank it takes a large fee and takes a long time.