Why? Look at Nxt. It is clearly the next Generation of Crypto Currency. Where does this leading position come from? Definitly someone, who is involved in Crypto-Dev for a long time. Someone for whom Bitcoin is from yesterday. Nxt is Ethereum..right now 
Nxt isn't ground breaking enough to be called "next generation of cryto". PoW is still better than PoS, if you weight in all the pros and cons.. dont get me wrong NXT is great, but not enough to dethrone BTC.
Not groundbreaking enough?
Voting, asset exchange, monetary system, plug-ins...
What do you need? gosh, have you seen the wallet? Compare it to bitcoin QT !
When i see the debate around the block size in bitcoin, you just can't say this. Nxt is one of the few decentralized coins that keeps innovating, over and over, despite the bitcointalk trolls.