There are myriad reasons from simple ignorance of technology to fear of disruption of an already shaky financial ecosystem (fiat currency). I’ll just touch on a few perspectives…
You have to look at it this way: the first entry-point of information and intelligence on a disruptive technology like Bitcoin is via popular news sources and “trusted experts”. Many of these commentators and critics are not familiar with the technology of Bitcoin and are only looking at it as a currency, typically under the erroneous assumption that Bitcoin is *only* a currency (discounting the entirety of blockchain tech potential).
Some people actively want to discount Bitcoin because they DO understand its potential and how it could hurt their interests. Big Banking, certain investors, etc. However, the sentiment is slowly changing as the SEC considers how to best regulate something that we all know is not going to go away, or fail.
As for the layman: they hear about the market “crashes” and the clandestine use-cases (illicit markets e.g. the darkweb). They hear about fraud, money-laundering, a lack of KYC and AML procedures. The non tech-savvy assume anything is easily hackable, when a blockchain is notoriously difficult to disrupt (see: 51% attack). They worry about Bitcoin’s violent market fluctuations (to be expected of an infant technology). Many people don’t even realize we haven’t had a gold standard in decades (approx. 80 years), leading them to think “Well, the USD is backed by gold; what backs Bitcoin?” New financial markets make people wary, especially if there is a ton of disinformation and lack of understanding. Admittedly, the crypto space has not done the best job in educating neophytes about the technology – we DO need more newcomer-friendly resources for learning.
Bitcoin is intimidating, confusing, and risky to both the layman and seasoned investor alike. The underlying problem is looking at it solely from the metric of financial markets. It’s easy to forget about the promise in Layer 2 solutions like the Lightning Network, or Schnorr Signatures when you’re focused on making money.
Even those educated about the tech have their misgivings: Bitcoin is slow, PoW consensus consumes MASSIVE amounts of resources, and the ICO regulation debacle isn’t pretty. However, these individuals need to consider the rise of the internet and TCP/IP protocol – it’s almost a perfect analogy. People thought the internet was absurd and dangerous; now it is the backbone of information. We need patience and good regulation to allow developers to make Bitcoin more viable.
In the end, I would leave with this single, definitive opinion: Bitcoin is a very young technology and is still finding its place in many ecosystems. It’s not perfect, but it has immense potential to overcome its shortcomings (as it has thus far). Ultimately, people are looking at it from the wrong perspective: it’s tech – it needs time and space to grow – and it will.