In the budget documents, they are using a 5% rate of return, which means $1 million of passive assets earning that $50,000 of passive income. I would agree that it probably is too low, the reason being that there are a lot of businesses that need passive assets in order to weather the economic storms. They need to save money so that when there's a downturn, they spend that money to keep their employees hired, to expand, or just to stay afloat, so $1 million of passive assets is probably not enough for a lot of those active businesses.
On May 1st, 2018. See this statement in context.