It's easier for the richer-than-poor users (average) to criticize the prizes & system because they're already up there on the "status ladder".

Think about the users who are roughly new to the community and are struggling to gain TC. Winning one of those tournaments serves as an accomplishment for said users, and it actually motivates them to play on a daily basis. Naturally, we want users to keep playing the game.
The reason you see these users being able to afford things is because their hard work and perseverance paid off after a prolonged period of time, which is also something we like to see.
If you think about the tournaments' purpose as a whole, you also realize that they're a great alternative for when the GMs aren't able to host, so it works both ways.
You can't expect to be exclusive with your TC forever, everyone deserves a shot.