Serbs liked it because our implementation was different (albeit also unsustainable), and we were not forcefully dependent on the Soviet Union.

For example, my father was able to buy a Beta VCR in the late 80s on his engineer's salary, it took him three months of intense saving.

I think the latter was the main reason why. Serbs were not Soviet puppets, USSR could not control them, they didn't feel occupied by foreign power. So even if Communism kinda sucked, it was more like "dumbass politician we elected who keeps mismanaging things" rather than "foreign enemy who's yoke we must get off our butts".