Agreed. I thought that Ford should have offered the Supercharged V-6 from the T-Bird Super Coupe in the Mustang as an option. It was lighter made good power and would have been a hell of a car. But as mentioned it would have cost more than the 5.0 and sales would have suffered.If I were one of the bean counters down at FoMoCo I'd axe the v6 Mustang, no doubt about it.
Why keep an n/a v6 around when a turbo 4 can make similar power, more torque and achieve better fuel mileage? BMW 3-series, MB C-class, Mk V-VI GTI, and a few Audi's went from at least an available 6 cyl down to exclusively a 4 cyl turbo and they're selling well.
What you have to keep in mind is that the majority of your average non-GT Mustang driving crowd could care less what's under the hood. As long as it looks like a Mustang and can move under it's own power, they're happy. And a ~250hp turbo 4 can provide that.
And who's the buyer for an EcoBoost v6 Mustang? In the F-150 the EcoBoost is a more expensive option than the 5.0, something that wont fly amongst the faithful. Save for a few members on here, i'm guessing the majority of GT owners will opt for the 5.0 over the EcoBoost v6 any day, even if they produce similar numbers.