to my knowledge well ur wrong...
I did the first 360 king kong to gnome hack see here
YouTube - XBOX 360 King Kong Shader Hack to Gnome Live cd
during this time access to the 360 was very minimal at first but eventually it improved and no the hypervisor was never conquered and all 3 cores still arent accessible to this day...but that original hack did lead to drivers/libraries being developed which led to xbr(hacked dash thanks to access/knowledge from previous hacks) and running with the broken signatures and 3 cores (wink wink) and heck may have even encouraged or helped dispersed stuff like xlast, hacked dev xb1emu, the official sdk being released in the overall scheme of things
but back on topic GEOHOT ur my hero...!