Because... Windows? Plenty of thumbdrive and portable harddrive manufactures make use of this 'feature' to show a splash menu/crapware launcher on insertion of the drive, so I guess they like the idea.
I think it depends on the users interested in the /new section. Most of the people just look at the home, while there are some users who watch the new submissions, and when they miss, the submission doesn't make enough points to get to the home. (OK, maybe we all know this, but ...)
Didn't the attendees realize that there would be a post-test at the conclusion the security conference? That's what the USB stick experience was. Can't wait to see what "grades" attendees received :/