Great points. Studying people that are proven “successes” ignores luck as a factor and results in a Survivorship bias which is a specific kind of selection bias.

As David McRaney explains in his You Are Not So Smart Podcast (incidentally one of my Top 3 Podcasts You Must Listen to in 2016), “the entire advice industry is a monopoly run by survivors.”

In reading such stories you don’t hear about the people who religiously did X every morning and were never successful. Nor do you hear from the successful what not to do because they likely don’t know.

For a more detailed explanation here’s the relevant excerpt from McRaney’s book of the same name.