I'm of 2 minds on this. I want to say every works stands on it's own but experience has taught me that more content from an artist really can taint an earlier work.

Seeing more content, especially flawed content, dispels a lot of the rose colored glasses effect people tend to have.

Sometimes an aspect of a future work reveals the author's true meaning in a previous work. A true meaning that ruins the whole damn thing.

Sometimes the author is outright self destructive and uses his future work as an outright "Screw You" to fans for whatever reason and does everything to ruin his own product.

And of course sometimes it was always pure crap, you just didnt realize till you were drowning in it.