You won't hear me defend the quality of writing on Stargate: Atlantis
. After the first season, it was mostly dreadful.
Having said that, Stargate: Atlantis
at least had a sense of humor about itself -- usually -- which often (though not always) made it watchable. (The number of qualifiers speaks to my low regard for the series).
SGU abandoned the sense of humor completely, and replaced it with forced interpersonal conflict, dull characters, empty mysticism, and a pace that could be absolutely plodding.
SGU also absorbed many of the tropes of (better) serialized television dramas (shuffled chronology, secretive characters, pop song wrap-up montages, handheld photography, and more) without knowing how to properly use any of them.