I agree with your reasoning. I think it's sort of silly to suppose that selecting $55 implying a high discount rate is necessarily less rational. If someone offered you $1.00 today or $1.03 tomorrow, it would be a very strange person who decides that they would prefer the $1.03, even though that's a 4,848,172% rate of return. There are actually disutilities involved in keeping track of future cash inflows, even if small. But almost no one, even the triumphantly rich with very low marginal utilities associated with additional dollars, would prefer $55 million dollars now to $75 million dollars in 60 days. Perhaps drug addicts and the terminally ill would.

Of course, if someone said "Occasionally throughout your life we will surprise you with either $55 dollars, or $75 dollars 60 days later than the days we would have surprised you with $55," it would then be silly to choose the $55 dollar scenario, because in that case there are no disutilities.

Interestingly, the survey data actually doesn't seem to support the notion that those with higher incomes are more likely to take the money now. In fact, the data suggest that the wealthiest are slightly less likely to take the money today. For five quintiles, the P($55 now) is 8.4% for <$7,770, 6.2% for <$25K, 6.8% for <$50K, 6.4% for <$83K, and 5.0% for the top quintile. This is with N=593. This doesn't include any analysis for potentially confounding factors.