Why You Should Avoid The Smith Machine. The Smith Machine looks the same as if you would do free weight Squats, but safer. It’s, however, different. Here are 3 reasons you should avoid Smith Machines:

Less Safe. Force your body into fixed movements patterns. This can cause knee/back injuries. And the fixed bar doesn’t prevent accidents.
Less Efficient. Build less strength & muscle since the Smith balances the weight. Expect Squatting less when switching to free weights .
Little Carry-over. Technique is different using free weights since you have to balance the weight yourself. You’ll have to relearn technique.

Stabilization means shit to bodybuilding. And core strength is not a priority, again, if one is bodybuilding orientated.
IFBB Pros use both machines (including the Smith) and free weights as tools to means to an end. The free weight only hardcore mentality does not apply.

The smith machine squat is meant to be done similar to a leg press (except you're standing instead of lying on a bench/chair). Mainly targets the quads. And no, it is totally different than barbell squat. If you're more into athletics, smith machine squats is pointless.

If one does the smith machine squat using barbell squat technique, he is in for some wreckage.
Core strength might not be a priority, but squat is still a pretty usual exercise for BBer. However, I do I notice that advance BB'ers tend not to prefer it.

A strongman/powerlifter, no matter how much he diets and does cardio, will never, ever have the level of complete muscular development of a bodybuilder.

For a bodybuilder, functional and core strength is secondary. It doesn't matter how much you lift, how much you look like you can lift is important. Pretty muscles popping out through our shirts and pants is what we want. Still.... doesn't mean we lift sissy weights. =) We just love looking good and looking like we workout.