Screwed by the Network: Moving the series (Stargate has always been a Friday tradition) to Tuesday nights, with no significant lead-ins (twenty year old Star Trek TNG episodes after Caprica was canned), in the middle of the Fall season, in the same timeslot as two of the most popular shows on television? There was no way that would go wrong! This sums it up well.
While it's safe to say that the Sci Fi Channel execs have gone insane, much of SGU's difficulties might also be due to the fact that it was too different from its predecessors, and not always in a good way. Fans complained about the series lacking humor and likable characters, among other things.
Some of which many say were gradually addressed by the second season, at the same time Syfy insisted that overly long hiatuses and virtually no marketing were the order of the day.