I pay 5 bucks daily just to have lunch delivered at work.
Paying ten bucks to enjoy a good game and support the dev in making more of it doesn't sound so unreasonable to me.
People who put their games up for free so any random freeloader can enjoy them makes less sense to me, though I occasionally end up paying more in donations to games that didn't charge up front... but the vast majority will simply take free stuff for granted.