Don't forget that the prize earnings aren't even enough to cover the gear needed for the prep. Why do that when she could cruise and collect giant amounts of money from delusional fans, mostly girls looking like walking beanbags living under her "I'm all natty" delusion.
She's got two options:
Fry her liver and perhaps place second in a show nobody watches
OR
Cruise, sell merchandise for tens of thousands of dollars, promote her business and increase sales.
Oh I didn't forget. Its a losing endeavour if you're a woman. The "science" behind prep has gotten to the point where even a $10k winnings wouldn't cover prep. Food alone takes up a huge chunk of out the budget, then you have to add in the gear, coach, travel, hotel, tan, etc...
I think DLB is doing what's right for her. Rob also realizes this, and is milking it for all its got. Assuming they don't divorce, they can cash huge now and do whatever the fuck they want in their early retirement. Not to mention, they have other streams of revenue.