Yes, mobile platforms aren't the best option for some games, but there are many thousands of games where touchscreen works very well - it all depends on what you really want to play. Before you jump on me, I'm not saying that touchscreen or mobile gaming is better, it's just different but still can be very enjoyable.
Then there's also the MASSIVE point that mobile games can and do make money for the devs, whereas devving for (dead) OS consoles will barely get a thankyou. An awful lot of time and work goes into making a game and it can be very disheartening to not get any feedback, let alone thanks. Financial gains can help in that regard, especially if it helps fund the next device. Kudos isn't going to fund the next big thing.
Plus, while there is still life left in these old machines they are massively underspecced (nowadays) and just can't do everything that a dev may want to do - the screens may be too small or the CPU too slow or GFX chip can't handle enough pretties etc. etc. Yes they are still capable of producing some stunning games, but to get them as good as a dev might want takes time - why go to all that effort when you can do the same game on a new system without all the hassle? Drag & drop tools now exist (for new machines) to make making games easier so why bother struggling to get a game running on a GP2X when you can get the same game (or better) running on an iPhone quicker and easier.
You are looking at the issue from a consumer point of view - most devs are probably looking at these machines from the opposite side. What is it actually worth to them to continue to support dead systems?
Can I ask you (and it's not an attack), what you have personally contributed to the GP2X, Wiz, Caanoo or Pandora? If the answer is "Nothing" then I challenge you to create a game that you would want to play on any of those machines and then wait for all the kudos. If you have contributed and continue to do so, then congratulations and well done, but it's not easy is it.
I don't dev as much for any of my machines any more as my circumstances have changed somewhat, but I will never, ever get rid of my old machines and always consider if whatever game I'm working on will work on any of them. Simply because I can.
However, the real question here is is it possible to get devs to come back or to make the scene more active?
The answer is probably no for the long term. However, In the short term you could make an incentive for devs (new and old) to create stuff for the GP2X etc. Maybe a competition or something that will make them want to come back. If you make that incentive worthwhile, people will come. If you make enough incentives regularly people will also stay. Thing is, can you come up with an incentive or a range that will entice users back?
