If those things are required, then why do so many immigrants become entrepreneurs?
Most of the people from poor countries I've known in NZ had domestic help and owned property back home.
Also, immigrants usually do not carry cultural dead weight - once again I refer to Germany. Starting a company is not really popular here, as you will be socially shunned if you fail (even if you not end up bankrupt in the process, but that's another can of worms). Germans are risk-averse to the extreme, immigrants usually not.
Since I'm also German, I would like offer a different reason. I frequently observe people on HN talking about their "side projects", where they build a simple app or website in their spare time, and people are willing to pay a dollar a month or so, which (when summed over maybe 1000 users) makes for a decent secondary income.
When I consider such a model for myself (just as exploratory thought because I don't have a nice side project idea ATM) it quickly devolves into a nightmare where I spend all my free time filling out tax report forms so that the Finanzamt can collect taxes on my maybe 100 euros per month.
Maybe that's a misconception and it's much easier to operate a side business as a one-man show, but that's the mental image in my head, and that's also the main reason why I would be quite reluctant to even consider just a side project.