[sgornick]

Miners are receiving nearly $100K USD per day but the share to the smaller operators is often just small amounts, oftentimes $20 or so per month. The cost for them to cash out using the bank system is often expensive. This provides an economic method to cash out small amounts without incurring high fees.

[enmaku]

More to the point, they won't actually have to cash out until they're ready to make a purchase with their proceeds. This means more money kept in Bitcoin for longer instead of being cashed out to sit in a USD/EUR/GBP bank account somewhere.