Are you telling me that a random chinese company can make a system with a better screen than the gp2x and that is easier to make a custom firmware for than the gp2x? Wow.
Well GPH is pretty incompetent overall so yes, just about any company could do a better job. But when did anyone say it was easy to develop custom firmware for? As far as I've heard it comes with firmware and some built in emulators, which will probably never be updated, there's no documentation and it's not meant to run unsigned code so you'd have to reverse engineer it. Who knows what OS it even runs, or if it's something entirely custom. There are hundreds of shitty MP4 players so the company will probably stop making it out of nowhere and refuse to provide any support except to use it out of the box as they intended.
You didn't read the thread from the link that was in the post I replied to, did you? People said that they could remove or edit the firmware, test things out, and it would not brick. That is so long as it is in "firmware mode". It also runs on a blackfin processor, which, I guess, has a port of linux for it. That's why ryleh, an avid programmer in this scene, was so interested in it. Plus, that company only seems to make a handful of mp4 players. And so what if they drop support for it. Just look at the gp2x.
I don't think that GPH helped very much in anything other than releasing the system and the firmware's source.