they should have revealed the killer in the last episode...

Apparently they didn't want to reveal who the killer was or at least Lynch didn't want to.

I recently watched the original series for the first time. Plan to watch fire walk with me soon then the new series. I've only seen a few of Lynch's films and while I enjoy the visual style he has im not keen on their ambiguity.

I feel like I came out of his films knowing less than I did originally. He has stated the best part of a mystery is the mystey which is true but I prefer to get some answers and see if im right.

I didn't know if I'd like the show because of this. I enjoyed the random clues that made sense later on but can't see how the show would have survived if they had never revealed the killer.

I suppose it is like a dark soap and they wanted to add other storylines but I don't think any of them where as good as the main mystery

I agree with this 100%, All of the episodes after they revealed the killer (with the exception of the finale) were so bad and hard to watch. I want to forget that the Ben Horne civil war plot or the terrible actresses that played Evelyn and Lana ever happened.