I've visited the link you provided but unfortunately, it is broken.
Make sure you check the url that everyone has shared before you leave. This is the reason why many people say that not all site shared in a post are safe site. Always check and be alert for safety.
[url=http://https[Suspicious link removed]cutive-says-millennial-generation-investors-prefer-bitcoin-over-gold]Article [/url]
Anyway, I think the reason behind it is that Millenials are mostly into using the internet, they exposed online so it is easy for them to access Bitcoin and other crypto compared to Gold. Another hypothesis is that because Millenials are love to take the risk no matter how big it is, knowing the Crypto market has an undeniably high risk ahead of it.
Theres a reason behind all the millennial frenzy for the asset they want to invest in. Bitcoin is one of the phenomena in the last 1 decade, it change thing in a different way than before. Transaction, usability, convenience and price are what bitcoin has. As an accepted payment system and transparency is what makes it superior.
The limited number of bitcoin and the high demand have made it a high-value asset, the volatility poses a risk, but can also benefit anyone in between. Big risk are a consequence of high expectation, big profit and so on. The price of bitcoin can change from time to time and so on, so your economic status will also change if you enter and invest in it before 2017 until now.