And for me the beauty of the bitcoin was to solve in elegant way the "consensus problem" in a distributed system ... that was a stroke of genius
And what happens to be if the next "stroke of genius" happens to be Proof-of-useful-work?
The internet is well and alive, Usenet fairly deserted and the Gopher protocol replaced some wierd little startup called Google. Nowadays the only part of the internet that most people know is the web. Well, "Web 2.0" as they call it.
"I tell ye, back in the days, it was madness. We were just wasting leccy on solving stupid crypto puzzles. And now? The CureForCancerCoin has already found treatments for 37 different variaties of cancer. Thanks to the SearchForFTLCoin the communication to mars takes less than a second. We used to have higher latency between Australia and the States often enough back then. Ah ye, CryptoCurrencies 1.0, what a waste. But we used to love em anyway."
I predict, based on my own personal feeling and opinion, that the alt coins you mentioned will totally fail. You can take that to the bank.