Another thing to consider, though not likely:
If a leased vehicle is in an accident this does not effect the buy-back value.
If a purchased vehicle is in an accident, the private party resale will depreciate appx 10-15% below market value (due to informed buyers + services such as carfax = accident history).
To me, it is a real comparison of short term Vs long term. The most basic way of putting it is when leasing a car, you are essentially paying the depreciation value + a bit more for the time you are the registered owner. In some situations, it will certainly make sense; in others, not so much.