Bringing in a bunch of unpaid interns (or worse a paying interns) and treating them like professional employees sounds like a recipe for disaster on both sides.
From the studio side you now have an unreliable workforce that your managers are going to have to spend extra time babysitting and dealing with work that isn’t that good or late. Then all the other professional artists at the facility have to deal with a bunch of eager, but really time consuming people running around asking basic questions. Anyone that goes through this whole process that is any good will probably leave the studio once they get good (because the studio is relying on a student workforce to minimize costs, not hire professional artists with experience). Once you get someone trained up and reliable they disappear.
From the intern/student side you get to start out at a facility doing production work but you are the lowest rung on the ladder with absolutely no creative input. You will have to work really hard to make sure you get a chance to sit down at the different workstations to get experience using software and feedback from other professionals if they have the time and patience to help you out. Then when you are done you have to go to your second job so you can afford to eat. If you get sick or want to take a long weekend it isn’t like you get sick leave and vacation time so you look bad against the other bunch of interns.
I see the value in paid and unpaid internships, it is a great opportunity for someone to get some real production experience and learn some production tactics you just can’t get from a school program. However, as great as it is for students it is a burden on the studio and a potentially abusive setup for the student.