Why end when it was so good?

A show that runs for four seasons is bound to have its suckish moments, and I found my interest waning a bit sometimes in the fourth season. But Season 5 had some great writing, which makes me think that there was potentially more creative energy where that came from, which could have fuelled a bunch more episodes.

Was the show really insufficiently popular enough to warrant only six episodes to wrap up in a final season?

It seems they found a creative seam for Season 5 but that that it was cut short, resulting in too many questions about characters that could not be answered in just six episodes, such as what occurred with HG and Claudia's brother.

Oh well. I enjoyed this show from the start to the end, and I will remember it fondly.