Most 3d action games have extremely few gameplay programmers, they just pick an off the shelf engine and then most of the technical work is optimizing the graphics pipeline.
Ive worked on AAA games for the last 8 years, and I made my own 2d games for 5 years before it. My current project has something in the region of 60-70 gameplay programmers, and has been this scale for the last 3 years. Writing gameplay code and engine code are two very different experiences with different constraints. There is plenty of technical work in writing good gameplay code.
