Science, like music or art, is one of those things that you do because you decide that you like the rewards it brings more than the struggle that is required to achieve success. If you are rich, the risks of doing it are lower, but being poor hardly stops you.
If you do any of those in order to produce finacial gain, it is pretty dumb, as there are easier ways to make way more money if you have the potential to be successful in those feilds.
The professor saw that the guy didn't have any real passion for science, and thus told him to do something else.
The real quote i disagree with is "This is the basic theory behind the practice of tenure of professors in American universities. First, a recent PhD graduate must first steel oneself and complete 5 years of hard work. Afterwards, if you are picked by the group of tenured professors and one day pass their requirements, then for the rest of your life you will never have to worry about making a living again. At that point you can wholeheartedly devote your time to research and study. Naturally the school also knows that the overwhelming majority of these tenured professors have no research potential left in them. Equally impotent are the lowly menial workers of the research laboratory. However, out of the vast numbers of tenured professors a few stand out from the crowd that actually have talent and contribute positively to the economy."
Science today needs a lot more menial laborers than professors directing research, because it works on grants and doesn't generate its own income, professors are perfectly happy to take people who are not really interested in the work, but will be methodical and will work for very low pay (like asian PhD students) because they need a lot of hands to run these tedious experiments. That doesn't mean that once a professor becomes a professor they are useless or lack talent. It seems as though he confuses positive economic contributions with positive intellectual ones (which might only be capatalized on decades later).