Bank Negara is likely to raise rates due to our economy expansion to cultivate saving and to control money velocity in country. It is just one of the monetary policy or measure to sustain our economy. This rate will provide banks a `benchmark' for doing their business. If the charge higher rate for their financial products, i.e: Loans, they will get less customers. If the bank charge lower rates, they could have attractive marketing campaign to shout about but they would have to forgo or earn less from the difference.
P/s: Correct me if I am wrong.