His step father was an immigrant from Cuba who came to the US at 16 without being able to speak English. His father ran a bike shop.

That's old money?

Ordinary people buy houses for far more than $300,000.

...with a mortgage, and the house tends to maintain value. They don't have that kind of money lying around to throw into a risky business.

Not being willing to take the risk is very different from cannot raise the funds.

$300,000 is simply not an outsize amount of capital to start a business. People do it all the time. Expect to put out $1.3 to 2.3 million to start a McDonald's franchise, and those are everywhere. (Other franchises are less expensive, not more.)

The idea that one has to be rich to raise $300,000 is simply not true.

The ratio of people I've met who've taken out a mortgage to the number who've taken out a house-sized business loan must be well above 10,000:1. It's not clear that you're arguing from any basis in reality to suggest that they're the same in any way.

That's why those 10000 do not create Amazons. It's not that they cannot. It's that they will not.

It's like Bob and Ted have an equal financial position.

Bob: I just borrowed $10,000 and put it into Bitcoin!

Ted: Haha, you fool, that's so risky!

--- 5 years later ---

Bob: My bitcoin is now worth $1,000,000!

Ted: That's sooo unfair!

And remember, Bezo didn't have $300,000 either. He borrowed it.

The median home price in 1994 was $105k, so it was basically three houses back then.