Inclines and flat bench presses are equally important for developing the chest. Yes, the incline version targets the upper pecs moreso than the flat variation, but that does not mean it is superior for overall chest development. The flat bench press recruits more overall upper body muscles, which allows one to lift more weight and get bigger. Incline bench presses do not work the lats or triceps as efficiently as the flat version. I think everyone should do both, although I personally prefer inclines. I do agree about shoulder/rotator cuff injuries--inclines are far safer for trainees with shoulder conditions than the flat bench. But if you have an injury due to an imbalance, focus on the imbalance instead of neglecting a productive exercise like the flat bench press.