Because the entire appeal of gaming is that you make choices and master the game. It is fair that a person spending 20 hours earns more credits than a person playing for 2 hours, gamers accept that. It is because the advantage was earned in a fair in-game and everyone had an equal opportunity to get it.
You don't go and tell players from our Eastern Europe that it sucks to be you because you aren't making as much income as someone with a 6 figure job. If you treat non-paying users as second-class players and make their game harder because someone with a fat wallet can use a better ship/weapons, then it is a shit game like those Chinese MMOs which we all laugh at.
F2P games might get away with light paid advantages because most people are smart enough to realize that if they don't pay for the game, then someone else has to pay for it. SC isn't a free game so don't expect gamers to go light on its paid advantages.
And if the game sells in-game advantage, then you open a pandora's box of whether the game deliberately pushes players towards buying their way into ships/weapons as opposed to grinding for them in-game.
And how is EVE Online doing? Is it a growing game, or is it a rotting MMO with a dwindling population because nobody wants to start a game where they are going to be literal peasants with no prospects of ever matching veteran players?
You still do not understand that this is sandbox, not theme park game and its not singleplayer game.
There are so many variables and so many different opportunities to get wealth/fight instead of one player farming for 30 hours and then he/she meets other player that farmed for 5 hours and then they PVP. This not a world of games like Star Citizen or EVE.
And EVE was growing every year for 11 years. I dont know how were their last two years though.
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To describe it more in-depth
In EVE i was able to farm like 5$ worth of currency per hour, i lost ships worth 60-100$, i killed ships worth 300-500$, i even killed one worth 500$ and looted it in high security system, in other months, I earned money speculating some specific market by buying every item from this type and selling it with 30-40% higher price, which took me like one hour a week and earn me quite good money, but it was long time investments, etc.
You can play game where you turn off PVP flag and stay in high security systems and just doing missions or play cooperatively, and gaining wealth.
Or You can play like me, exploring uncharted territories or fighting for power in low or no security zones with other corporations, you can pirate or be high risk trader.
Those are all valid ways to play and all are valid ways to get wealth, some faster, but come with risk, other are safer, but slower and more boring.
Thats a way it looks and plays in such games.