Same as why is there an SCDF when there's a police and fire brigade in Singapore. Or why there's a People's Defence Force when the Army is made out of people already. Or why there are so many Ministers in the PMO or why there was (or still is) a SM and MM and soon to be EM (Eternal Minister).
By even saying the above, it just show you are a big fucking moron of whom cant tell the difference between SCDF and police and know nothing are which unit belong to where.
And with such ignorance, you want to oppose PAP. No wonder opposition in singapore got nowhere when we have people like you saying and doing al;l the dumb things.