I’ve got a couple theories on this. They’re both stupid.
Mostly I assume the guys who go to the draft to watch it live are extreme fanatics. Either their team just picked somebody they think is a wasted first pick, or, the team they hate just picked the guy they wished they could have. Or their Jets fans and just naturally angry. Or Colts fans and just happy not to be in Indianapolis. The whole spectacle is pretty Roman, which makes it gay. For football, which is clearly not.