Here's are two interesting factoids courtesy of India's Economic Times newspaper:
1. System D/informal enterprises account for 15 percent of all manufacturing in India.
and
2. System D/informal enterprises account for 90 percent of India's economy.
Of course, that makes System D critical to the future development of the country. Indeed, if System D accounts for 90 percent of the Indian economy, it doesn't make sense to leave it out of any economic development strategy.