Stalin was establishing a collectivist system. He had no reason to exterminate workers. The alternative explanation to Stalin being ‘short-sighted’ is that he forced the issue of collectivism. The kulaks preferred to destroy what they controlled and starve the nation rather than cede their privileges.
History has shown that the ‘collectivist way’ eventually made the soviet economy grow faster than any other economy until, of course, China recently. Soviets became a world power in record time starting from destitution and being simultaneously fought by the US, UK and France. Was the price worth it? My opinion is no. The price was too high.
However, today, the world is faced with a similar choice. End capitalism or fail to i) address climate change, ii) the threat of nuclear war and iii) the transition to China being the new world power. Will the capitalists cede power gracefully or would they rather destroy the world?