If the most desirable and highest paying jobs require long periods of unpaid internships. Only kids from wealthy families will be qualified for those jobs.

I understand the logic here and agree that in effect, that's what this does in cases where there are unpaid internships for prestigious jobs, such as in entertainment. However, I've never heard of an unpaid internship in any high-paying industry aside from entertainment/fashion. Finance, Computer Science, Law--the standard in those industries is paid internships (often highly-paid too). I was explicitly warned by my program to never accept an unpaid internship offer. In my experience, unpaid internships tend to exist in industries that are already lower-paying: journalism, (some) marketing, humanities-related jobs.