No, you can certainly work out your lower chest. I meant that working lower chest is not going to help make your chest appear less flabby. I was also trying to say that you shouldn't focus on lower chest as the main component of your chest routine. For instance, I would hit flat bench, incline bench, db bench, and then do some weighted dips at the end to finish it off. It's still okay to do some lower chest work for sure, and weighted dips are a great mass builder in their own right.