If you've been following this team closely and watching more than the odd Leafs' game every now and then, the deeper issues this team has are more obvious. As for the obvious: ""this was the Leafs 22nd game without a regulation win in their last 24 outings". (Note: now 25). That's not a mediocre team. That's the level of an expansion team. That's a team in trouble.
They lost again last night vs. Washington, 3-2, in pretty much the same way they've lost every game. It was a game they lead 2-1 with 10 minutes left in the third. They tried to sit on said lead by playing "defense first" hockey (note: Still not sure what this means to Carlyle aside from double shifting the McClement line when the Leafs are leading). However, given their puck possession and defensive issues they once again coughed up said lead, and unfortunately (or fortunately if you're already hoping for a high draft pick) they didn't make it to a shootout like they're done A LOT this season. Once in the shootout, they've been having ridiculously good luck this season. The points they've gotten in this skills competition has gone a long way in hiding the fact that they can't hold onto a lead or win in regulation.
The problems/reasons are numerous. The Leafs' defensemen are either young with piles of potential (and make the mistakes expected of such a group) or refrigerator-sized and molasses slow at skating - a dangerous combo for all the wrong reasons. The exception is the Dion Phaneuf/Carl Gunnarson paring, which gets a ton of flack but is leaned on in just about every important defensive situation and is predictably looking exhausted lately. The team also leans completely on their first two lines for any and all offense. Carlyle dresses goons every night he barely plays, putting added pressure on and exhausting the other forwards. And there are some real, legitimate disconnects between the coaching staff and players that have been seen in the last dozen or so games - most guys ignoring Carlyle when he's talking during time outs, and James Reimer, who is acknowledge as one of the nicest, calmest guys in the NHL being uncharacteristically, visibly angry on a consistent basis.
The fact that the East is ridiculously weaker than the West has helped to disguise the Leafs' problems. It has taken about a dozen games longer than it would have in the West for the Leafs to start dropping. Some people point to Dave Bolland's injury as the turning point, the moment when everything started going downhill. Sure, he played well, but one guy can't make up for the fact that this team has so many issues - being unable to clear the zone, needing Phil Kessel or Joffrey Lupul to score every night just to have a shot at winning, giving up more shots against than worst teams in the league, and relying on your goaltenders to have elite, game stealing games every night just to win. These aren't minor issues.
The worst thing is it was all predictable. If you follow any of the fan sites, especially Pension Plan Puppets, people who follow the team closely have been calling this from around August-ish. They foolishly bought out Mikhail Grabovski's contract. He was a guy who was a solid offensive contributor but didn't fit into Carlyle's system - he was put in the role of a shutdown D forward last season when he's never played that role before and predictably failed - so was shown the door. He had more talent and desire than most guys on the team, and losing him was huge. They also chose not to resign Clarke MacArthur, who has been Ottawa's best forward on more than a few nights this season. In their place they signed Bolland and David Clarkson and somehow expect them to elevate the team. Bolland was doing great, admittedly, but again the problems with the whole team were there from the start. Why they thought Clarkson would be better than he is makes no sense. His stats line is actually worse than guys like Kulemin, who is acknowledged as a 3rd line shut down guy. Yet he was picked up to play a 2nd line, offensive role. He doesn't pass unless he's playing with Phil Kessel, and gets terrible penalties at the worst times (his "gritty" play last night lead to a 3rd period penalty and ensuing goal that ultimately lead to the loss). Anyway, that's a whole other rant.
While I wouldn't call this team a disaster, they're definitely not mediocre. There's potential but there are also a lot of problems and they need a shakeup.