People seem to be split about 50/50 over whether or not the suspension was extensive, but this shouldn't come as a surprise to anyone who's been following what Roger Goddell has been doing since first becoming commisoner.
Roethlisberger isn't being suspended so much because he may or may not have committed a crime, but rather because it was covered in the media so extensively and gave the NFL bad press.
Combine that with his history, and at least some evidence to say there was a chance that something did happen that night, this is the result.