I wouldnt agree “if you can progam your a maths wizard”. Im a pretty decent coder and im not a maths wizard. some of our best programmers at sega and im sure its the same for other places arent maths wizs. sure it helps but alot of game code requires very routine maths.
As for quaternions true about them being useful for camera systems, but really alot of the libs etc do those operations for you, so some people can treat them as black boxes for want of a better word. Although if your jobs is to write these libraries (which mine is\was), then ya you do need to understand them fully.