The concept entirely predates modern ideas of science and research, so it is no real surprise that it does not serve that purpose.
As a quant, you can be doing ML to predict the stock market or hard core network coding to make placing orders faster.
In a data scientist job you'd be doing data mining to gather insights about whatever area your company works in.
At a company like Google or MS, you could be developing/implementing interesting algos for search, ad targeting, etc.
This is not even to mention Google/FB research, and even more so, MSR where you could be doing even more researchy stuff.
Now it's possible that the above jobs are much scarcer than the support function jobs but I mean most of the world does mundane jobs and earns way less than you. A PhD gives a much higher chance of getting a less mundane job.
I think he was pointing out that what is doing is not that relevant to advancing human knowledge. Proprietary trading strategies and optimizations that will most likely never be made public are not any better.
All of your examples are the same until you hit Google/FB research where you might actually be working on something that isn't directly promoting the bottom line of your employer.
On the other hand:
* I think if you consider "tech, finance, data scientist", some reflection reveals a discouraging fact: we're usually not talking about science or even engineering at all, but essentially support functions allowing new kinds of productivity or scale for mundane business functions. So there's careers out there for us educated in these quantitative/technological arts... but it's generally not a career in science.
* More concretely, my math/CS education is almost entirely superfluous to my six-figure job doing CSS and wrangling squirrelly JavaScript frameworks/apps (mostly as a support function to sell automobiles). Meanwhile there are tenured faculty making half what I do (and postdocs/grad students on poverty incomes) actually working to figure out how life works, cure cancer, and build space elevators.
I don't know much about research related to tenure achievement and salaries, but I found these:
http://chronicle.com/article/Average-Faculty-Salaries-by/126... http://www.opia.psu.edu/sites/default/files/AIR_Tenure_Flow_...
My takeaway from skimming is that (a) faculty salaries vary, those in areas with the industrial options we've talked about seem to be higher, but an average of $65-70k seems credible (b) data on tenure is hard to come by but everyone agrees it's very difficult to get at high status institutions.