That chart is the balances currently being held at the bittrex exchange, not the distribution of all Nxt. You want something like this https://nxtblocks.info/#section/blockexplorer_distribution
Psudo-anonymity can be achieved by not linking your address to yourself, plus a core coin shuffling mechanism is on the way.

Everything on Nxt is open sourced and freely available https://bitbucket.org/JeanLucPicard/nxt/src