I've just gotten a new computer and a new OS, so I'm getting back into DX after being away for a while. I also noticed that the majority of the themes are the same ones I saw a couple years ago and wondered about that. I imagine y'all are right about the resolution issue being a big factor, but I don't quite understand that. (I actually just got a new monitor myself while in the middle of making a theme and so it's something I'm dealing with). Yeah, it takes a little more effort, but if people are willing to make skins that have umpteen flashy lights and such, you'd think making a couple versions or making them resolution independent wouldn't be a biggie. If you look back a couple years it was standard practice to make versions for two or three resolutions, if the thing wasn't res independent. Actually the theme I'm working on right now is going to be a pain to make resolution independent, so I may have to make a couple versions. Don't see the big deal. Maybe people have just gotten lazier? *shrug*
Maybe as OS's start to have more customization built-in people are less into doing it themselves?
Personally, other than simply getting busy with other things, the biggest reason I periodically stop working with DX is that so many themes just don't work/don't meet my needs. I think I went through every theme going back to 2004 the other night and only found about 5 that were anything like I was looking for. Of those, 2 made my computer pretty much explode. And, I suppose if you are frustrated by just using the themes, you probably aren't going to want to go even further into it by making your own. (Though personally, I just find that a challenge to do better).
As far as making themes myself... well, I've never actually finished one. Lol. My problem is being a perfectionist. I don't wanna just throw something together that's been done 20 times. So I end up needing to get into major scripting, which I don't know how to do, and so I give up - thinking I'll get back to it later. By the time I do, there's a whole new version of DX out and I have to figure out new stuff, etc.
(Actually the theme I'm working on right now has minimal scripting so hopefully I'll have it done soon - keep an eye out.

I'm also working on teaching myself VBscript and my brain hurts, but hopefully I'll get it eventually and can start making some interesting things).
RR