People in cockpit mode would get stomped by people using the current view. This isn't a sim, why do you want this?
As long as you fit the same angular field of view to the screen It doesn't make much difference as long as the top half of the screen isn't very cluttered by static overlay art. For that matter since the developers seem to be philosophically opposed to HUD/cockpit instrumentation with a high degree of functionality I suppose you wouldn't want more than maybe 10-20% of the screen to be covered with static art.
With well designed cockpit instrumentation in the lower half, you'd actually have a substantial advantage over 3rd person view (not that that would ever happen, but it doesn't violate the rules of physics, just the rules of "you must be this crappy to be included in the GSF interface").
As to why you'd want this, some people prefer to maneuver with a zero parallax view for vehicle sims. For MMO character control you need the 3d person view because it offers a lot more peripheral vision that really helps in difficult combat situations. In a vehicle sim, the 3d person and 1st person views tend to offer about the same field of view, and having a camera view that's much closer to the vehicle's axes of rotation can be a significant advantage when it comes to ease of pulling off maneuvers that involve narrowly avoiding collisions.
With a lightweight art overlay I'm not sure you'd loose any net visibility compared to the space the ship graphic takes up in the area just below the center of the screen.
As for why GSF in some ways lags a 20 year old game, well X-wing was a SW starfighting game where all of the developer resources were devoted to making a good starfighter game. GSF only gets a fraction of the SWTOR team's resources, it may have been a fairly substantial fraction at times, but it's a non-core element of the main product so it really can't get the same sort of dev devotion that a stand-alone space combat game would get.