The PS3 does not have motion sensing, case in point. It has a tilt sensor that functions soley off of gravity.
Your entire arguement about it having "motion sensing' is moot because you obviously don't understand the technology in both of them.
The Wii controller requires you to aim at the sensor, which picks up the direction the Wiimote is aimed, this is "motion sensing".
The PS3, however, only picks up on the "tilt" of the controller, which only requires internal sensors.
It also has a secondary sensor that picks up translational accelleration. This is what happens when you suddenly move the controller in any given direction, thus creating artificial gravity (g forces). It works in 2 ways, up and down, and left and right.
It's limited only by imagination, as is the Wii. You're attempting to compare to completely different types of technology to support your arguement, and it simply does not work.
THe PS3 controller is not intended to have it's tilt function as it's primary method of control, it is an addition to it's already present control functions.
The Wii, however, uses it as it's primary method of control, which would mean it's equally as "limited". There are only so many motions you can do.
Point it to look around.
Swing it.
Wave / Flick it.
What else can you do that's so innovative and not limited? There you go, your arguement is done. Let's end it.