I find it helpful to think about blockchains as the next step in the fintech ladder. Imagine you want to represent ownership of a company, i.e. stock. You don't need electricity to do that. You can accept orders in person, record ownership in a book, issue paper certificates, etc. However, when the mainframe was invented, it became easier to track ownership electronically. Using electronic transactions also made it possible for many more people to trade and expanded the types of products offered, e.g. options became commonplace. Now, the blockchain has arrived. It does everything a mainframe at a large financial institution can do, but it opens up the platform so that more complicated transactions can happen and democratizes the platform so that anyone with a computer can write their own smart contract.
What we're seeing now is akin to the the dotcom boom / bust in the late 90s and early 2000s. A new technology has appeared on the scene which leads to two things:
1) People get ahead of themselves. In the late 90s, people could envision all the cool things the internet would unlock and tried to start businesses to realize the potential. Many of those business ideas would be viable today, but the tech wasn't there at the time leading to a lot of empty promises being sold. Today, people can envision how the blockchain will lead to the securitization of everything, but the tech isn't quite there to make the transition yet.
2) As with any optimism boom, there will always be crooks ready to separate a fool from their money.