Oh, well,
OpenGL is already an abstraction, DirectWhatever is an abstraction, SDL is an abstraction ON TOP OF THOSE.
That does not mean any negative or positive. It only means a lot of you have to learn a lot about architecture.
For the simple minds (and advanced X platform programmers) SDL is the easiest to learn. But both lower level ones are almost just as easy or difficult.
In the end it is always: I want to write a game but I know jack sh*t about matrices or basic collision detection math (isn't even in opengl) and I don't want to learn it. Won't go...
The basics is simply a vector x,y,z,l,r.f.b,u,d That's a nine vector matrix.(81 square) It's simple. Not counting gravity...
and some other...
Positive is if you can solve matrices, you can solve game programming.
Sigh.