I am talking to quite a few people who are investing in crypto and notice that very few have a broader investment spectrum. People either focus on ICOs, some small caps, others play it safe and stick with the high caps or established projects.
It seems like your mind is a bit prejudiced - while rotating in this market people possibly focus solely on crypto and avoid talking about their investments both in crypto and other options.
I also agree that is easier to trade stocks, simply because the volume is so high that a few whales or big investors cannot influence the market as easily by dumping their shares. The stock market is also much more regulated, if someone is being caught doing washtrading or spoofing the consequences are dramatic. In the crypto world manipulation is something that poses a constant threat.
That's what I've been constantly talking about - lack of regulation for all those scam coins destroys the belief in blockchain as it is, resulting in what's been happening on the market for the past 6 months - deep downtrend which is unlikely to end in the nearest few months. I know that anonymity and making quick money has driven many people here crazy, but it should not go like that anymore.