Currently you need to use their weird NDK and wrap it with Java code. For example, there's no way to play audio without using the Java SDK.
Many of these problems have been fixed in Android 2.3, but it takes ages for updates to ship out to the majority of devices (a good chunk of devices still don't have Froyo).
The other thing is that there is lot of choice with Android - $29 LG Optimus to the upcoming Playstation Phone. People who just need a phone that can browse and email and occasionally play Angry Birds - LG phone is for them. People who want a portable gaming device which can be used as a phone - they can get the PS Phone and it will come with Gingerbread.
I don't think that Android not having this or not having that is a real problem. If there is demand, some vendor will fix what is required, push more capable hardware etc and people will have more choices. So far the Android users don't seem to be demanding RageHD style games - that's all.
My comment was due to the way it's stated, "even possible on any Android device today", meaning that even with excess dev time, the application could not run on the newest Android device.
RAGE works on all the iPhones that support iOS 4, which excludes the original iPhone and iPod touch. However, the hardware on those are reasonably identical to the second generation of devices, so that restriction is an arbitrary one by Apple.
This is probably true. The fact that the current Android SDK requires wrapping OpenGL calls in a Java layer is cited by developers (it's mentioned up-thread) as a hindrance in writing highly performant games. Gruber chose his words carefully though, this is true today but the next Android update supposedly fixes this. We'll see.