Baler wind guard

When I was baling this year with the Hesston 5580 it clogged pretty bad and I had to take the windguard off to clear it out. because I was in a hurry I left it off. Now I've been reading on this site that some people hate them and leave them off and some people leave them on. Which raises the question what do they do? What purpose do they serve? I'm sure they're on there for a reason I just want to make sure before I put it on if it does something major to help.

Baler wind guard