For me it was the 2nd Edition that killed it. The big kickstarter with the fantastic art, then bizzare changes to the setting some of which seemed they were there to remove sexism but at the same time that removed core motivations (you know fighting against it, or being an evil sexist) from some of the characters in the setting.
Then the resolution mechanic seemed to change most encounters into a cake walk unless the GM could come up with an increasing number of complications for the players to deal with on the fly. Also the clearly unbalanced firearm damage meant any character skilled with a brace of pistols could instantly win pretty much any fight.
Really wanted to like it but the more I read the less I did, and when it actually got played, my players quickly realised it could have done with significantly more playtesting and feedback.