This may sound cynical, but people like to hear a point of view they agree with. By being less partisan Al Jazeera is pissing 100% of the people off some of the time.
One thing I observed while watching them - they have a very distinct pro-Arab bias. It's readily apparent if you watch their reporting on the occupation of Kurdistan and the occupation of Palestine (Arabs are the victim, whether they are the occupier or the occupied).
That's partisan, but very few Americans have much of an opinion on it. The small minority with an opinion are pro-Israel and think Kurdistan is in Russia.
Since the Kurds are not Arabs, I'm assuming the bias is against the Kurds?
You are right though, they are partisan. They're biased towards the Palestinian cause, for example. But they still give all sides a chance to voice their views.