I'm pretty sure they ran the numbers for potential profits and determined it's a goldmine - in the long run. Maybe they'll need to increase the lifespan of satellites. Their internal launch costs are pretty low already. Amazon wants to build it's own constellation and is building new glen partially because they can't get launch slots from SpaceX. I'm sure you can find some numbers to do some napkin math.

Theoretically they can serve the whole world with internet without requiring only minimal land based infrastructure. That is a gigantic market they can reach. And incredibly power to wield for such a psycho.

Another strange case is high-frequency trading on stock exchanges - because light is faster in the vacuum of space compared to fiberglass they can trade on the stock exchanges around the world like nobody else can. Not sure how much money that makes.