"...and setting aside the jealousies and ill-will continually subsisting between Fanny and Lucy, in which their husbands of course took a part, as well as the frequent domestic disagreements between Robert and Lucy themselves, nothing could exceed the harmony in which they all lived together."

Mrs. Ferrars, Lucy, Robert, Fanny, John all deserved each other.

Tongue in cheek, in Jane Austen's world, I do I think life is fair! :) As you mentioned, the punishment of living life with themselves is punishment, indeed!

But seriously, I do think the remarkableness of Jane Austen's work is the fact that she paints a picture of right and wrong in her narrative so subtlely - and fleshes out characters that, due to birth and situation - reflect the society of the times and often show the unfairness of the economic and political system of the day. It's more remarkable when it is pointed out (e.g. - the behavior of Lucy due to the unfortunate circumstance of birth and education.) Self-awareness and understand others is usually rewarded with happiness in JA's stories, I think.