The residential solar industry installed less in Q3 than any quarter since Q1 2015, a shocking turnaround for an industry that should be becoming more competitive. But the report put the blame on installers like Sunrun (NASDAQ: RUN), Vivint Solar (NYSE: VSLR), Tesla (NASDAQ: TSLA), and SunPower (NASDAQ: SPWR) focusing on profitable customers rather than growth as the reason for the decline in installations.