Because it's not 10 000x harder to manage SpaceX than Joe's Plumbing. Sure the compensation should reflect in some way the effort and difficulty. But these earning ratios between the top and bottom or big and small are out of whack. Parent points out that they don't mesh with people's sense of 'right' either.
If Musk drives SpaceX into the ground, he will be hated universally and possibly jailed, given how much the U.S. now relies on his technology for access to space.
If Joe drives his plumbing Co to the ground, he likely won't make it to the local evening news, much less be infamous forever, across the entire planet.
