I felt like the developers went with FPS in order to sell more copies.
Well maybe for Bioshock 1, but I dont think they could have done anything else with what is basically Bioshock 3.
I definitely agree that the gameplay was not quite as developed as the aeshetics and story. The rail sytem was pretty dumb, at least when it came to combat. It did fit in with the whole setting though.
I really didn't like the selection of vigors. I had like one or 2 gotos, and the rest I barely used...even with combining them.
Besides TLoU, one one the best story lines I have played this gen tho.