I think this is a false attitude that comes from a rather egotistical belief that engineers can 'do anything' -- so just be an engineer and then do other things

I think this is a false attitude that comes from a rather egotistical belief that engineers can 'do anything' -- so just be an engineer and then do other things too. Have you watched an engineer design an interface? Its not their speciality because they simply don't have the time to concentrate on such things. Have you seen them write marketing copy? Create HR requirements? Cast product visions? They usually aren't good at these things because it isn't their speciality. Why would anyone argue that engineers are good at everything and ignore the concentrations that yield very real and measurable value to the products.