How does one separate the outer mold line of the spacecraft from its performance?
Isn't Buran's appearance driven by similar requirements vs. aesthetics? What else would it have looked like — if you want lots of crossrange capability, you're not going to get something that looked like Faget's designs, would you?
Buran had different design requirements (once you discard the political), because unlike STS the orbiter wasn't sole launcher of the system - Energia took care of shipping heavy cargo to whatever orbit you wanted. So they had different set of constraints including size & prospective contents of the cargo bay.
They have also flirted with the idea of just putting two jet engines into orbiter for extra cross range, which was probably not an option on STS given the huge dead weight of engines
It wasn't needed because the STS wing area achieved the goal of not overflying the Soviets after dropping off a military satellite (once-around mission out of Vandenberg SLC-6), and the US had many politically friendly potential landing areas, while USSR did not.
Catering to NRO and USAF wartime requirements doomed the STS to cost overruns. Sticking with Faget's designs and the NASA requirements may have salvaged the program's cost goals, but I'm no expert.
Isn't Buran's appearance driven by similar requirements vs. aesthetics? What else would it have looked like — if you want lots of crossrange capability, you're not going to get something that looked like Faget's designs, would you?