Well, some of them are hard-working, talented people with an eye for good writing, perhaps even writers themselves. However, I'd say most readers can barely tell time and wouldn't know a decent script if it sang Hallelujah and burst into flames. In my opinion, these people are dangerous. They throw out good scripts and recommend crap simply because they don't know any better. It takes a hundred people to say yes in this business, but it only takes one unpaid, no-experience, college dropout to say no.
Readers are a good place to start.
The number of scripts this person had written breached double digits, yet nobody was interested in any of it. Not long ago, a friend of mine told me that her sister had taken a job at a major studio as a reader. These are the people who read our work. These are the people who send our scripts to the next level or throw them out the window. Our careers are in their hands.