Since US regulations make it more difficult for citizens to participate in crypto investments the growth shows an underlying interest.
You're obviously not from the states, because it is still legal to invest in bitcoin and everything else except for ico's. The only regulatory pressure anyone is getting is facebook with libra. There are also some laws pertaining to exchanges which is why Binance doesn't provide service to all states, but it isn't a nationwide issue. So it's nowhere near as bad as you think.
people like OP tend to believe whatever lies they read online. it doesn't even have to be from a source like a news site, it may as well be a random comment on a forum. so he might as well be from US but fallen for the FUD.
First you don't know OP so, therefore, you don't know "people like"..
Second the source is quoted and linked so take the time to click and read -- rather than just spewing nonsense. If you question the methodology of research than put up your supporting facts or sources.
I doubt that you can predict the price of Bitcoin based on adoption. The volatility proves it's not linear so you really have no clue.
Lastly, many of the investments in crypto for retail investors come from ICOs, IEOs and exchanges. Each of these is more difficult to participate in the US unless you are an accredited investor,
and many of the projects exclude US participation outright due to regulation and uncertainty.
I would trust the source of the research and quoted data more than your random comment on a forum. And I am from the US .. all my life.