It is my personal opinion that unpaid internships favor only those who can afford work without pay. This being said, they favor the wealthy.
Working without pay is not just not having income, it is wasting valuable time that could be spent working even a minimum wage job and earning more.
To be able to work without pay is to have the means to live without income for oneself; as in coming from a comfortable familial background. However, the job market is so terrible right now, in combination with the economy, that you need to have experience before being hired for any type of job. There are so few jobs one can go into without experience and the ones that do happen to hire the inexperienced do not pay to teach. Therefore, unpaid internships are only designed for the financially capable.
People who cannot afford the time to work without earning compensation are therefore at a lesser advantage than those who can afford it.
Those who are able to hold these internships are then put at an advantage over those who cannot by holding the upper hand in entering the workforce. This even holds the disadvantaged saving up to enter the workforce to hold the unpaid internship: they have to wait longer and therefore have fewer job openings than those the same age may have taken. The already limited job market is limited more for the person from lesser means; a fault at which is not there own.
The way our capitalistic system is set up is designed to give the advantage to those who are already privileged. This is inherently unfair.
In order for at least a fair entrance into the workforce, internships should be required to pay their interns. With this requirement, anyone could accept an internship in pursuit of their long-term future, without the concern of their day to day survival. That way the most experienced and qualified person could take over openings, and therefore each job will be done to the best and fullest extent.
This will help the economy in the long run and just allow for more opportunities for all people.