You're right, we're agreeing violently. Above, you said that more rich people started a company than worked for others; here you're applying Bayes. That first assertion is not verifiable, but you're definitely right that starting a company increases your likelihood of becoming rich.
That depends entirely on your definition of rich. While P(earnings > $1M/year) is probably going to increase, P(earnings > $100k/year) is probably going to decrease. It's also unclear whether your expected earnings are going to increase, and note that most people's loss function is not even linear (e.g. you're not going to be 10x as happy earning $1M than earning $100k -- and you're going to be much less happy when you're broke).
It's ok, I could have been much clearer (but then I would also repeat what's in the article). I have the feeling people commenting here did not read the whole article or are just nitpicking, it's one of the best articles about the history of work and its current status I have ever read, everyone should read this.
Also, apologies for my rude tone. :(