i've heard that complaint a lot, and while it is true to an extent, it doesn't entirely take away from entertainment value! for example: movies (well, 99% of them) require no brain-power to enjoy, they are pure entertainment. i look at games like DS, NWN, and Diablo as interactive films. even more so now with the new 3D engines that allow seemless camera control (i map camera functions to wasd, like i would with an FPS). this ability to control the camera and main characters gives me the feeling of directing a film.
i guess it's all in what you're looking for. i go into a DS game not expecting to use my mind, or powers of strategy and planning, but to get immersed in a story taking place in a beautiful and imaginary world.
- tron -
"tron is big and tron is full of action... it's a hell of a ride!"
-from the Tron 2.0 box