This is in the middle of the desert at high altitude. There are basically no local people who aren't associated with the telescopes.

https://maps.app.goo.gl/cWgWx1RKjEUjavPn8

Whether the facility is built there or 50 km away, it's going to have to draw people from more than a few km away. The entire Taltal district only has about 11,000 people.