People pay you, so that they dont have to go out and mine themselves, because it is boring.
There's always been a classical divide between players of either having fun or doing the chores.
It is to this extent, plus partly knowledge and skill levels, that enables grafters to obtain mu from those engaging either at a less intensive level, or at a high power level in, for example, crafting.
It is one of the reasons why automatic play is generally a bad thing, as it automates away the boredom that is a lifeblood to some of the players in the system...
Yes, the crux of a theoretically massive game with a real economy
Edit: as server space costs have come down, I have argued for a travel time component to and from rewarding areas as well in much more expansive areas to research.
Unfortunately, although space mining could have been an even more voluminous 3-d haven for hard-to-find resources, MA made the resources a guaranteed find within the scope of set asteroid types and stuck the fields mostly close to space stations (apparently). They also introduced a randomish conversion system for tailings, a main component of mining loot that then averages asteroid miners' mus, regardless of where they did their mining.
I almost don't know how MA could do things worse. Having only extractors planet-side that extract at 1 ped per hour might indeed be worse, but in space the slow mining bit is shooting afk from minutes to ages at non-regen bits of rock ...
Mining now seems more snafu than ever - and I don't even mind boring, tbh. It can be relaxing!