when I was 16 I remember spending my entire workout working them lol. I had 8 pack washboard abs.
I would tell you that if you do compound lifts that you are working them just fine... sometimes I will grab a med ball and a 25 pound weight and do some core work with that.
the muscles that 99% of guys fail to do ENOUGH OF, even long time vets are the back muscles... a lot of us have huge front delts, pecs, even traps.. but not only is there is a massive imbalance there but our front muscles stay tight and the reason for that is because of our jobs we have today sitting in front of computers.. every single person reading this is guilty because I am assuming you are on your computer right now right? so instead of worrying about your abs worry more about your back and stretching out your front muscles especially during work.. learn some wall stretches.. otherwise what you will have is neck and back pain that can become chronic long term. that's why I tell guys to work their legs too, and not just their upper bodies. its because you have to be balanced!!