If it were peer-to-peer like bitcoin that could be enough. But it isn't. It is peer-to-masternode(s)-to-peer.
You can't and never will be able to verify what masternodes are doing, as long as they appear to be doing what they are supposed to. But what else they are doing you have no idea. At all.
That's why there is the 1000 DRK requirement for a wallet to function as a masternode. To prevent and deter bad actors from just simply launching millions of nodes for free. Darkcoin is still being developed, and is moving to a direction where the masternodes know less and less about the details - the latest step in the evolution being masternode blinding. By the time NSA gets interested enough DRK might be running totally hidden under TOR or I2P on raspberry pi 3's or custom made Darkcoin hardware.
It is though quite possible NSA proof anonymity simply cannot be achieved if you ever want to use a computer or a phone, or IoT in the future.
What can be achieved though, is keeping your finances private from your neighbors, friends, relatives, employers, competitors, insurance company, bank, police, local authorities, irs, etc, and to keep your coins actually fungible. This is the flaw of Bitcoin that Darkcoin aims to fix.