exaclty, because we never hear about it, they get quietly disposed of in what ever manner that nations desides, probly true for alot of radicals really.
we only see it when it devolves to the point where the state as an entity has essentialy collapsed, and its become a stright up fist fight between various factions, like the fall of persia after the sha left and the islamists and communists went at it to fill the power vaccume, the islamists won in the end.
the onyl time communism wins is when it adopts practises that arnt in line with communism, and the end result is dictatorships like under stalin, mao and the jong uns.