It's not really an exception to a rule anymore though. With the way games are made today -- with bloated teams and huge budgets -- the need for more junior design positions has increased. Even linear, level based games often have at least a couple of more junior design members who may be responsible for gameplay object / prop placement. This is just how games are made now.
But yes, going back to my original point. Filtering potential candidate for junior design members by whether or not they have a degree is -- in my opinion -- a silly thing to do. You're probably missing out on some right gems! Pretty much all games development jobs should be judged on how well said person can do the job they have applies to do. I don't see the games industry like law, medicine, accounting etc. You can't demonstrate your ability to do those jobs through anything you can SHOW employers. In games you can.
Yes, a lot of people will become good at their preferred disciple through going to study. But it's the fact they are good at their disciple which persuades me to hire them; bit the fact they have a piece of paper saying they know what they are doing. SHOW me your skills, don't tell me about them.
So as I said before; if a designer can SHOW me their design ability, then I'd have no issue bringing them in for an interview. Piece of paper or not. I'll be able to judge their potential team, communication and other disciple related skills in the interview process anyways.
Apologies if this post is filled with mistakes. Writing on my iPhone.