Silly question regards "Superbible" camera class

Why Superbible authors implemented all the transformations by themselves instead of using glRotate and glTransform? The same about matrix multiplications? Why not to leave matrix staff to OpenGL? We can always retrieve needed transformation matrix.
If I need to implement FPS camera for terrain rendering - is there any inconveniencies by using only OpenGL functions?


Because the fixed function pipeline has been deprecated in OpenGL 3.0 and removed from the core profile of OpenGL3.3 and above. So now if u want to do modern OpenGL using the core profile, u need to handle the matrices yourself.

Ofcourse if u use the compatability profile, the fixed function pipeline is available.