It wasn't just them, the Czechs didn't care much for them, thats why you don't see a Czechoslovakian SKS or Ak.. They pretty much snubbed all of Russia's designs and even went as far to design and manufacture their own caliber, the 7.62x45, while it was slightly superior to the x39, Russia forced them back to the x39, but even under the Soviet's pressure, they still made their own weapons of their own design, the Vz 52, Vz 52/57 and Vz 58, even the Vz 61 series. Same with the Tokarev and the Makorov, the Cz52 and the Cz 82 pistols.