What "take risk" means is that you should try to be entrepreneur in situation where you can fall back and be well paid programmer again if it does not work out. Or that you should risk someone elses money.
EDIT: I guess good rephrase would be that "take risk" usually means "overcome irrational fear when you are in perfectly safe situation". That is what actually people mean.
"Sell everything and fund my startup" is fine when you've got a 12 month emergency fund, living in a paid-off home, , and you parents are able to bail you out. It's not fine when failure means you're penniless and homeless.
Further: it's much less of a risk when you have a metaphorical rolodex of wealthy friends from university or business school. You're not cold pitching - not even slightly. Doors open for you, instead of being slammed in your face.
Yet they'll tell you shit like "Try hard enough and you will succeed! I worked long and hard, people saw that, and were willing to invest. Good hard honest work is rewarded."
The people working on their startup 12 hours a day who don't have connections have no idea that the bit left out is that "people were willing to invest in my idea because we chugged beers together in the basement of Sigma Chi."
That's not so much about being a billionaire, but about diversification.
Fortunately, even people of very modest means have access to diversified index funds these days.
If you have a few thousand stocks in your index fund (eg like VWRA or VT), then in doesn't matter how risky any individual stock is (like the startup in your example), as long as holding them has positive expected value.