RIAA and the MPAA are middle men.
Not really. They're associations.
Middle men don't add value: They don't produce the product, and they don't use it. They're worthless. Fuck them.
The "middle men" you're referring to really aren't the RIAA or the MPAA -- they're the record producers and movie studios. The MPAA and RIAA are just trade associations -- they certainly aren't middle men.
Albums can be produced by a band on their own without a record producer, but to claim that the producer adds nothing is wrong. He does provide assistance of various sorts -- technical, capital, access to a distribution network, etc. There's a reason bands are looking for recording contracts -- because they provide at least the chance of success.
Now, these producers tend to rip off the artists much of the time, but to claim they don't add value is wrong.
As for movie studios, yes, somebody can make a home movie on their own. But to make a major movie requires a studio and massive amounts of money. The movie studio is a whole lot more than "middle men". It's not like you can throw a bunch of actors in a room and end up with "The Avengers".
Now, the distribution network -- those people really are middle men. But without them, the record or movie generally doesn't make any money. Yes, there's a few exceptions, especially with albums -- bands selling their music online, for example. But for now, finding the right middle men often means the difference between making no money and making a lot of money -- that certainly does add value if you're trying to make money.