The short interest came from hedge funds that are currently doing redemptions. Those redemptions likely to continue for the rest of this week. The funds are selling large amounts of MLPs and selling short was a way to lock in before the actual sales and make $$.
The continued low interest rates make carrying large amounts of 30+ year debt great. Also have not had anyone suggest that demand for propane, ethane, or anything else is declining worldwide. There are too many people for that to happen and a growing middle class in India and other countries.