Read CfB's comments in context with the logic.
i) CMC doesn't include trading on the three decentralised exchange platforms Nxt has: Asset Exchange, Marketplace and Monetary System (and multigateway too, thinking of it. Though it isn't a core feature of Nxt).
ii) "Once everyone start using solely NXT its market cap will become 0, because no trades will be happening on centralized fiat exchanges" and centralized fiat exchanges are the only thing CMC reports.
The more Nxt moves to decentralised exchanges, the closer it will get to 0 on CMC as they only report centralised exchange stats. The decentralised stats are on the blockchain, but they just don't bother.
You are completely avoiding the fact that their are many ways to gather metrics as to NxT's falling marketshare within the crypto ecosystem as I have just shown. Even brand new coins like Stellar and Paycoin are ousting NxT when studying metrics other than market cap.
nxt is a crypto in constant development and doing research into the best systems, so I would venture to guess that statistics related to unpaid people helping out the platform, and developer, research and project development would slide in nxts way.
anything relating to VC money will be weighted against nxt as that's not the route we've taken