I was just wondering what the point of having the salt in the bags when the salt will just wash off the first time that you throw it in the water

Its also a packing material.  Keeps the baits from sticking to each other.

I think it's a gimmick.  I haven't ever had any baits stick to each other so much that I need salt to disentangle them.

You are probably right with some plastics, but its definitely necessary with others.  Go buy a bag of Venom tubes or Berkley Hand Pours,  wash the salt off, and take them out on a hot day.  You'll miss the salt.  

If the salt is poured in the bag it's of no importanceif the salt is cooked in it's of major importance

I'm a mechanic and my hands get beat up at times. Nuthin' like reaching into a salty bag 'o worms with cuts on your hands.

Like Francho said, some will stick together really bad if the salt is not present! The Yum Wooly Hawgs are bad about that!