Earnings have gone downhill courtesy of several Google algorithm changes, but I think the site as a whole has made some good moves toward better quality. Over the 6 years I've been here, the platform has gotten a lot more user-friendly, they're getting better at communicating writing guidelines and expectations, and they've tweaked the hub score to give a more accurate picture of how a hub stacks up. The changes they've made in about the last year, I think, have gone a long way to encouraging high-quality output.
I'll admit that I'm still working on all my updates for the new guidelines, and currently have almost 300 hubs that I unpublished because they're poor quality and need a lot of work, and they were pulling down my overall ranks. However, once you implement the changes, the earnings do start showing up again. It's still less than I made pre-Panda, Farmer, Revenge of Panda et. al., but it's slowly improving. As with any open-submission platform, it's still all about the long haul.