People seem to be focusing on the "murder mystery" part. That was just one example, they do this with every single quest that is not simply "The townsfolk say there's a marauding monster and point to a cave, telling you it went in there". Basically if I do not hand them the entire plot they do this.
Then they don't want to play your low level game. They started it, found they didn't like it. It happens.
Really? You don't think there should be any amount of work involved in the game? It should just be "here is a monster to kill, go do it"?
Really? You think the players should spend hours going back and forth while accomplishing nothing because they can't figure out the riddle of the lock combination holding back their answers? It should just be "here is a roadblock, throw yourselves uselessly at it."
See? I can throw your blindness right back at you. Maybe you should have finished reading the whole statement, instead of focusing on half a sentence.