You're underestimating a synthesizer. Take a look at a Moog sometime. There's a lot of knobs and dials, and they all do something (and most of them do something that was nearly impossible with any other instrument invented). A saxophone can't gradually alter its entire timber mid-phrase, the closest wind instruments have are the various kinds of mute, each limited in its ability in a way a synthesizer isn't..
I think you missed the point. A saxophonist with a wind MIDI controller can play a synth with a similar level of expressiveness as that provided by a keyboard plus pitch and modulation controllers. However, no Minimoog patch sounds much like a real saxophone. A physical modeling synth played with a breath controller can sound pretty good, but not quite "right". Kind of like how human actors in front of a digital matte painting look fine, but digital actors have the "Uncanny Valley" problem.
GP AC: "...it still will require some type of v-drum set to handle the different ways of striking the drum head." Similarly, a breath controller is very helpful for wind instruments. Many real instruments have special playing techniques that are difficult to completely emulate in virtual instruments.