I guess I go exactly the opposite. Theoretically, you can get more value out of carefully playing a narrow rewards program, but a simple cash incentive has its own benefits. Notably, you're not stuck within the confines of the available rewards, and it's hard to devalue a dollar balance as easily as announcing that a free flight is now twice as many miles.

I cashed out a cash-rewards card recently, and bought a work chair with the proceeds; I don't think most miles/points plans would have let me get that.