I think it's good advice to have out there to make it clear to people that if your primary, or only, motivation for writing is money you're effectively investin

I think it's good advice to have out there to make it clear to people that if your primary, or only, motivation for writing is money you're effectively investing your time in a lottery ticket and you ought to consider if you're comfortable spending that much time paying for a lottery ticket. For some it will mean they won't write. For others it will mean that they adapt to try to bring down the investment and increase the chance of success. E.g. submitting shorter works to magazines or taking editing or smaller writing jobs are both far more likely to pay off, and far lower investment. But if you're working on a novel because you want to write, then you should ignore the numbers in the article and write anyway, and see it as a sobering view of how little it takes to be a relative success as a writer. E.g. you're already doing better than most once you're selling in the low thousands, even if that isn't paying the bills.