This exact "greed" rhetoric is what helps businesses keep dev salaries down. You don't get greedy people for that much, you get smart business people (they know their worth and charge for it).
I do not understand devs who justify low salaries this way.
Why make 50% of your potential?
Exactly. If you are just greedy then programming is not the right field. Much more reliable to make a boatload of cash through other means if that's all you care about.
I think you're misunderstanding what he is saying.
I'm not justifying low salaries; i'm saying that $155,000 is plenty.
"plenty" by what metric? It seems to be less than market rate (for good experienced developers). What other metric should we use?
What do I have to sacrifice to earn 100% more money? There's a lot more money in doing harm than doing good, and I will gladly take less money to do good.
In this case, you maybe don't have to sacrifice much at all. There are plenty of good reasons to go work at a large software organization, e.g. stability, and most startups will work you harder for less tangible benefit.
Some people may be willing to take less pay in order to have more control/freedom in a small startup, rather than just being a cog in the machine at Google or Microsoft.