That's what I don't get either. NFL games are filled with jerseys. Why?
It is really pushed by the team itself actually. Lets them know who to push for local advertising based upon popularity.
I'd also argue that NFL Jerseys are generally of a higher quality than NCAA jerseys.
Aren't they all the same loose-fitting, polyester shirts with screen-printed numbers? Yes, I know there are the super expensive ones with stitched numbers and names, but those are crazy expensive. Also, what do you do when a guy leaves the team?
I have 2 NFL jerseys. I bought the expensive versions at a discount at the end of the season. Both players were signed to long term contracts before I purchased their jersey.