To me the two extra buttons somehow look... I don't know.. wrong?
Honestly, that's how many people who grew up w/ the SNES or Playstation see it. However, anyone who played a lot of Megadrive, Saturn, N64, or fighters will see it as completely natural. It only seems wrong to you because you are not used to it.
We already have 4 (!) shoulder buttons. Why two additional front buttons?
A second row of shoulders is not as efficient as 6 face buttons. I have no problems with their inclusion, but most 6-button games will be harder to play with that layout. Not to mention, logically, this really screws things up for things like N64 emulation, where the C buttons often needed to be in a cross due to their use for strafing, camera look, etc.
Was there ever a gaming console with more than 8 action buttons?
The first one that comes to mind is the Atari Jaguar.
-God Ginrai