This criticism is almost all correct, and believe me, I'm on your side.
That said, the criticism about oversampling wealthy people is wrong. This sort of thing is standard practice. For example,
Let's say you sample 300 people randomly, and it turns out that 200 are wealthy. You can fix this problem by giving the rich people's responses less weight. Essentially, the response of each poor person gets twice the weight of each rich person. If weights are used correctly, this isn't a problem.
This method is used by just about everybody. Census Bureau, Bureau of Labor Statistics, Consumer Expenditure Survey...etc.
That said, every other criticism here is correct.