Exploring does pay little for the most part but when you think about it, the pay makes sense.
1 - Everywhere that is near the inhabited planets have probably been explored 100 times by 100 different players.
2 - Earning money in this game semi-reflects a space fearing civilization. Traders are hybrid truckers/stock market brokers/gamblers buying and selling cargo/assets between systems. Explorers have to go deep into unexplored territory in order to rake in the dough and they have to have the right equipment. Combat pilots are bounty hunters, putting their lives and their ships on the line for a 'few' creds in a high stakes game.
If life was easy everyone would succeed.
The game is a grind but life is a grind.
I will admit that mining is probably one of the lowest parts of the game, specifically collecting the floating materials. Drones would make mining even in low yield sectors profitable.