Because in the world people currently live in, a small class of people own the means of production and the land you stand on, and everyone else has to have a job to access all of the necessities to live. Eliminating jobs means, quite literally, eliminating people's livelihood.

And that same class of people who own everything would rather kill everyone else and also destroy the planet than give up their position or allow any of the socioeconomic changes necessary to change the distribution of wealth.