Nah, money is not a needed award from racing. The game already has so many ways to make huge stacks of money. I've only been here 50 days, I play pretty casually, and my net worth is already closing in on 30 million.
Think of it this way too; racing does not cost energy or nerve. If it paid out money, even chump change, it would still be a "pay to win" strategy since you need points to get a racing license.