Why throw pizza dough besides for show?
A lot of it depends on the type of pizza you make. Where I worked we did thin crust pizza, and these were the reasons we tossed:

Speed. Trying to roll or pat out a 17 inch pizza would be very time consuming. 

Consistency. Was easier to make the crust a consistent size and shape.

Space. Rolling or patting a person needs the table space 100% of the time. When tossing you can step back from the table and let another person get in to prep (or finish) their toss.

Job marketing. People wanted to work there just to learn how to toss, and it helped maintain that "authentic" vibe.

And as you pointed out, the show aspect of it. Kids loved to watch our staff toss.