It’s just a time thing I’m sure. I’m not married, no kids, no commute (I work from home). That adds up to a few extra hours than most of the rest of the world has =). And it’s not easy either, I’m not able to help people as one-on-one as much as I used to be able to, and I don’t put as much time into articles as I probably should. I do work full-time normally, but at the moment I’ve cut back to half time at Chatman Design while I finish the Digging Into WordPress book. That thing is such a monster it’s taking up a ton of my time right now. Once that’s out the door, the articles on CSS-Tricks will certainly get more in-depth again!
Even though you are busy, I think those few twilight hours can still be pretty golden for you. You just need to figure out what is the most important thing to you and focus those hours on that. If that means your own projects, you might have to drop the freelance. Or vice versa.