This DTV visa is basically a way to get whomever wants to stay in Thailand for up to 5 years as long as they don't work in Thailand for a Thai company. Not so complicated to understand. The government is benefiting from it regardless just by people enrolling to courses and training and spending money on accommodation and other expenses
This is not an 'extension'. It's re activation. Two different things. Extension can be done while your still IN the country. If you need to leave the country it's 're activation"