A possibility I haven't seen mentioned is that the style guide of their employer, together with a few employers who pay out-sized salaries (Google, Amazon, Facebook...) could account for the difference.
Yes, the only reason to use spaces is because you are forced to because you work in an organisation that had to force this rule because it employs too many morons who cannot make the difference between indentation and alignment.
* Large organisation -> pays more.
* Organisation that has power to enforce coding style rules -> pays more.
