I am by no means an economics or marketing expert, but I think it's worth considering Bitcoin's "brand" impact and its history. Humans are irrational and do a lot of questionable things even with ample evidence of better alternatives to our choices.
Tuur Demeester makes a comparison in this podcast (https://www.theinvestorspodcast.com/episodes/bitcoin-masterm...) to Bitcoin/altcoins vs Coca-Cola and its competitors, starting around 1:05:20. He says that Coke had countless competitors trying to overthrow it as the #1 cola brand, but it stuck around as a result of familiarity and being of quality (my takeaway, not his exact words). He goes on to say that if Bitcoin survives with the same core developers trying to make it better and better, the brand attacks become less and less of a threat.
Plenty of crypto currencies exist other than bitcoin. This is only the beginning, and scaling is one of many issues that will be figured out. Even if you don’t buy coins, paying attention to the tech coming out can be beneficial and interesting.
YC-type people don't benefit from the VC system; YC is a subversion of the VC system, an effort to organize promise founders against the interests of VCs. Ceteris paribus, every YC founder would rather raise 5MM in an ICO than to raise them in capped notes or (even worse) directly from a VC.
If ICOs actually mainstream, YC itself gets more valuable, not less, as they control essentially the only noteworthy credentialing system for startups. Not to mention, they'll be the locus of all the selling-picks-to-prospectors activity that will follow.
Meanwhile: "congratulations" if you made money by buying and "hodling" back when 1 BTC was $1. People made money on Pets.com, too. So did the banksters who made money reselling bogus AAA MBS's. Nobody doubts that you can win large sums of money gambling on the actions of the greater fool.
But: it looks to me like most of the concerns raised by Bitcoin critics have played out as expected. Decentralized? No. Bitcoin is controlled by a small, self-interested group of big-time players. Currency? No. Bitcoin is a speculative asset. Seamless way to transfer funds? What are transaction fees for Bitcoin now? Here's approximately the trajectory of Bitcoin: in 2012, you could buy a pizza with it in 1-2 cities. In 2017, you can't.
And, as predicted, tens of other organizations have come up with their own competing cryptocurrencies. Many of them are objectively more sound than Bitcoin. But we're all meant to pretend that somehow, 1 BTC is worth $15,000 because it really is worth that, and not because Bitcoin is a distributed pump-and-dump scam.