My attitude is, look, I have friends, I have a life, I have things I want to do, I don't need the company to fill in these gaps. The only "rewards" I want are cash and time to spend it.
Buying vacation would just mean not being paid for that time.
Here in California, vacation/PTO is treated just like wages for regulatory purposes, including final paycheck.
What I can imagine being hard to buy is company holidays, but I'd rather have the "vacation" (read: cash) instead.
(My job allows you to "buy" extra time off, so it's not an issue for me; but I figured this was uncommon, especially in the States.)
The much larger sample size I have for a related question: is it any easier to take vacation at a company which offers 3 weeks instead of 2 weeks annually? To this, I've found the answer is "no."
Both situations have a simple explanation, which is that, except for the smallest companies, the person(s) setting the PTO policy is not the same as the one approving absences. That is, my manager cares about my availability, whereas HR and/or Accounting cares about how much I get paid during such absences.