You're not understanding that the fact that they made $3 million means they are not happy with sitting around with any amount unless they've become senile. Otherwise they would've stopped at $2 million, why not that amount?
It's not at all stupid of them to expect to make more money. They were successful, why would they not expect the success to continue?
Maybe this is why you haven't made $3 million and perhaps never will? This isn't supposed to be provocative but rather a logical and philosophical exercise.
I assume you could earn 5% annually with very very low risk. That's just 150k per year, not nearly enough to live a worry-free lifestyle and enjoy all the material things in life.
There's a story of a reporter sitting next to a hedgefund billionaire at a dinner. She says to him, "I don't know why you keep doing this. If I made a hundred million, I would retire." The hedgefunder replies, "that's why you will never make a hundred million."