Modern fighter jets are not rated solely on speed and manoeuvrability. Range, ceiling, avionics, weapons and all the rest are what make it a proper piece of kit. Dogfighting is low on the list of priorities in 2016.
Just like a few decades back - think F-4 Phantom II. High-power, low maneuvrability, only missiles... and then they had to identify their targets first. Oops. Those cannons were quickly added on again, proper dog-fighting capabilities were introduced back with other models.
There's also a reason why the A-1 Skyraider was kept on so long, much later replaced by the A-10.
I still think USAF would be much better off financially if they had a few more specialized planes instead of this jack-of-all-trades-master-of-none F-35.
I guess the real reason for this boondoggle is to funnel money to black projects, and of course pure and simple corruption.