Long story short: it's to protect against concussions 

Cam Rising got a pretty nasty concussion in the Rose Bowl game against Ohio St. Because of that and for fear of getting another one, he went and did a bunch of research on helmets and eventually settled on a relatively new one which is both lighter and larger and is supposed to be much safer and better at preventing concussions

From my persective, I get that it looks funny, but I can't get behind mocking someone for protecting their brain. It's one of the more distasteful things I see here (though I assume it's generally because people don't know the story, ignorance not malice, which is certainly better). Honestly, I wish something like this had existed for Austin Collie when he was in the NFL