39 years ago people didn't know about the dot-com bubble or the Great Recession.
No, you're shifting the burden of proof. The burden of proof is on you to show that hologram technology will exist, people will invest in hologram technology, and even more so to show that there won't be sufficient profit returns.
The fact that 40 years ago people didn't know about the dot-com bubble or of the 2007 financial crisis is completely irrelevant. Their ignorance is not proof of your assertions. This is such a large argument from ignorance
that I'm surprised your common sense didn't pick up on it.
If I were to tell you that in 20 years millions of people will spend thousands of dollars in order to buy a sex tape of Rush Limbaugh and Donald Trump and my proof of this was "20 years ago people didn't know Halo: Reach was going to be such a big hit," would you then find this to be a logical argument? Would you then believe my assertion?