They're boys. They're messy. Lol, it's like being confused to find a beer can in a college dorm room. Sure they could get a maid in there to clean 5 days a week, but it's easy to see that they aren't really embarrassed about it and it doesn't even occur to them there's a problem. Probably their moms will call and yell at them, but they won't do anything about it. Most boys are so predictable. Did they also say "this is where all the magic happens" when they entered the bedroom? Pft, boys.
I wish I could find the old video of Richards's and Carter's apartment when they first joined the Flyers. The coaches were warning people not to go cause they thought it was a disaster zone. Also complete with Mike joking that Carter went out to play in the playground when he was bored