Those 6200+ works already are available to the public, at minimum in scanned pages form, and most of them with OCR available. The argument that these works are "trapped" is a red herring stemming from frustration over how long it now takes the DP process to produce a "finished" version of the text.
Sorry, but this is NOT a "red herring". Looking at DP's own statistics on this subject, the release rate is about 2/3rds the project start rate -- and has been for many years. Why does this matter -- "eventually all projects will get released?" Yes, but by the time "eventually" happens enough more new books will be stuck on queues that it will continue to be true that the release rate is about 2/3rds the project start rate. This means DP is running in a "self similar" mode where effectively 1/3 of all projects that get started DON'T get released. Which means that 1/3 of all volunteer effort is being wasted. One might say "OK, let's just slow down the project start rate." If you do that then P1s do not have interesting projects to work on and they get frustrated and go do something else with their time. But DP NEEDS to have the P1s because DP grows those -- eventually -- to be the P3s and the F2s and the PPs necessary to get the queues unstuck. But the queues can't get unstuck because increasing the start rate to attract the P1s in turn clogs the queues. So again, what is the solution? 1) Increase the number of P3s, F2s, and PPs by reducing the qualifications. Or 2) improve the tools available to P3s, F2s, and PPs to make them more productive. DP can't fix the problem without changing. If you don't understand this, please take a closer look at the plot that DP makes available at: http://www.pgdp.net/c/stats/stats_central.php where you can see that one third of projects created DO NOT get released because they are stuck on queues. As more books get released it is also true that more books get stuck on queues and the ratio remains the same: 1/3 of books DO NOT get released because they are stuck on queues. Which means that 1/3 of volunteer efforts are being wasted by a flawed process.