Nothing is designed to make you pay for microtransactions. If they really wanted to do that, they would lower the price. If anything, it's the complete opposite. They're encouraging people to play the game. Kinda makes sense.
From what I understand, you can create custom races and alter the difficulty level. How is that boring and repetitive with hundreds of cars and 94 track layouts to choose from? Oh yeah, I forgot. A few very expensive cars can not be obtained within a few days. The I-want-it-now culture.