What did they have to sell? Michael Cera isn't a big marquee draw. The costly VFX may have played well, but didn't seem to draw people in. Edgar Wright means something only to indie filmgoers, and the comics played to an even narrower Comic-Con slice of the world. Universal marketed the hell out of this movie (I don't think they could have done much better, and they probably overspent) but it only played for the young smart demo. That's the Focus demo.
If you spend too much (in this case, the movie cost somewhere under $85 million, less some tax incentives, plus marketing) you are forced to open a movie wide. Other Universal movies that in hindsight could have been handled differently in less expensive mode: Green Zone, Robin Hood, State of Play, Duplicity, Funny People, Bruno, Public Enemies, Drag Me to Hell, Frost/Nixon. It's hard to say no to players like Imagine, Working Title, Ridley Scott, Judd Apatow, Sacha Baron Cohen, Sam Raimi, Michael Mann and Paul Greengrass, who demand budgets to go with their visions. But sometimes a studio has to do what a studio has to do.
Edgar Wright: he could have played in the indie playpen.