The story of aircraft development in the Soviet Union is an interesting one. Their air units were regiments of the army, and it was expected in the west that the army purges would cripple their aircraft design future. What happened was entirely unexpected, and I don't believe that anyone to this day can say how it came about. Design teams were set up and named for the lead designer(s)--so Ilyushin (IL), Mikoyan and Gurevich (MiG), Irkut (IR), Sukhoi (SU), Tupolev (TU), and Yakovlev (YA, but commonly known as Yak)--were operational before
the Army purges and show trials. In any event, for whoever's idea this was, they were under the aegis of the Peoples' Commissar for Heavy Industry, and were unaffected by the purge process, which devastated the Red Army in the few crucial years before the outbreak of war in Europe.
All aircraft design teams were required to meet three standards, in addition to whatever requirements were built into the orders placed. Those were the ability to take-off and land on unimproved surfaces, to take-off and land on ice and/or snow, and to take-off and climb in short distances. Though that may seem rigid, it stood them in good stead during The Great Patriotic War (as they called it), when they were unable to employ hard-pan airstrips, and were often retreating in the beginning, and almost outrunning their logistical train as the German war machine was collapsing.
The Foxbat is another mystery which I have not closely investigated, but what you tell me does not surprise me. It went into design in 1964, the year that Nikita Khrushchev "retired." His successor, Leonid Brezhnev, always put form before substance. was intolerant of anything smelling of reform, and tolerated gross corruption in his obsessional drive for "consensus" in the Politburo. That lead to stability in the party and the country, and a rapid socio-economic decline.
What you say about the Foxbat is particularly ironic in that Brezhnev was originally educated and first worked as a metallurgical engineer.