Actually I can think of several scenarios where I would pay the current pricing.
For example, a game I want is still $45 to buy.
If I'm not completely sold on it yet, a $5, 4 hour rental will be enough to know if I want to buy it. If I do, five extra bucks on the purchase price is no big deal. If I don't, it's better to have blown five on it than 45.
If I know for sure that I want it, but I know I'll play it once and never touch it again (and I'm too impatient to wait for the price to come down), renting it for $30 is better than buying it for $45 then getting $10 for it when I trade it in.