Dmoz isn't that much slow, I have submitted all of my sites and they were reviews within 7 days. Off course not all were accepted but we must keep in mind that they only approve those sites which meets their criteria.
The parked domains probably weren't always parked, but bribe an editor may be worth it to get it done. I'd pay $50 to get it done. DMOZ needs a paid option or a set donate amount. I think many would pay, and they could hire a few more editors.
And loose many too. We are volunteers, we like being volunteers, we want to stay volunteers. Any editor taking money to list a site when discovered will be banned and so will the site, permanently. Risky business if you have spent hundreds of hours of your free time building up a good reputation in DMOZ to lose it all for a fistful of dollars.