SB Nation's D.C. United blog Black and Red United writes that coach Curt Onalfu was fired because of his team's inability to score, something that's been a recurring problem with Onalfu's teams.
12 shutouts in 18 matches.
Really that's all you need to know.
D.C. United has had its share of injuries this season, just like every other MLS club. But the real long-term injuries were almost exclusively to defensive players. That doesn't explain 12 shutouts in 18 matches.
Black and Red United reminds us that Onalfu was fired at around this time last year from the Kansas City Wizards, also for underperforming. However, they acknowledge that Onalfu could be the scapegoat, and with a soft slate of matches coming up, interim coach Ben Olsen could look better simply becuse of that.