Vacation is also never mentioned in those discussions or comparisons. 10 days in the US vs. 20-30 (+ 8-14 public holidays, depending on the state) in Germany is much more important for _me_ than the net income.
Can't you take days off without pay in the US? The numbers that usually come up are twice the income compared to France. Taking 20 more days off without pay means losing a month of salary, which doesn't come close to making up the difference.