My opinion is that people are afraid because first of all it is a high risk investment because of the volatility of the market. Besides that there are some thresholds like:
- The high level of tech which is hard to comprehend for some people.
- The trouble it costs to invest in crypto/the low liquidity. Create your own wallet, buying at exchanges or websites, send through to other exchanges etc. etc.
- Crypto doesn't feel safe enough yet. This might also be because of the lack of knowledge or well known addressess offering these investments yet.

Just my 2 cents...