Everyone in that house is at fault somehow. The complaints by the guys were legit; the way they went about conveying their grievances with the ladies was the problem.
The ladies, for all of their talk about being adults and not needing anyone to tell them what to do, came off looking just as bad. If Katelynn and Devyn want to live like pigs, fine. They can leave their room looking however they please. When you're dealing with things that belong to everyone in the house, that movin' at your own pace sh*t doesn't fly. When people are coming right behind you to use dishes, sinks, or whatever, you need to show some respect for the rest of the house by cleaning after yourself.
I wish Scott would've kept the key for the rest of the season or until those girls learn to clean up.