Hmm... I looked through several of their games. I think we're definitely going to have a difference of opinion on this topic. Back when I first formed my premade and there were only a few people in it, I'd regularly play in PUG games during hours when my team wasn't available. These were inevitably stacked PUG games. I'd follow the simple premise of waiting for a game to show up with someone whose name I recognize as a good player as the host and join. They'd recognize my name and generally have no issue at all with me playing on their side. The games were typically 3v3. A 3rd player would usually join who was also quite good. Typically, no effort would be made at balancing the teams... why risk taking a loss by trading out an experienced player for someone who is not as good... also, the concept of balancing wasn't even discussed by people joining the games at the time. The majority of these games were not about finding excellent competition, but about playing the game and typically, at least for me, trying new strategies and builds. These games were generally nice, relaxing games that weren't highly competitive or challenging and increased my overall skill with various Dgs. They did pad stats and enable you to run with big win streaks. So much so that the ladder ends up becoming a representation of the people with the most time to play in this style of game.
And that's the way things will remain in this system, sadly. If you have enough time to play and you play SOLELY in stacked PUGS/Premades, you'll eventually rise to the top. That's the way the experience system is designed to work... whoever plays the most without losing moves up and up. So the system logically favors good players that band together either as PUGs or premades.
And for the part that some of you will disagree with me about even though it will sound strange: I really don't have a problem with people playing the game the way they enjoy it. If you want to get with your buddies and play a game online, have at it. If you enjoy less competitive games (caused by stacking), then go ahead and play those. I'm not going to think you are a great player even if you are ladder ranked number 1 until I play with or against you. And I generally don't care if you are ladder ranked number 1 because it typically ONLY means that you have more time to play than me. And even then, its only my opinion and you don't have to prove anything to me at all. It's just that stats don't prove squat. What I personally hate, is people lying about being a premade if asked, people joining PUG only games as a premade, and people intentionally trying to grief you. I don't really have any problem with people playing the game however they want to.
How competitive can the ladder EVER be if you can rise to the top by beating AI in pantheon or by beating random players over and over in stacked teams or stacked pugs? If we ever want there to be some sort of competitive ladder, we need to have the system revamped. Pugs play as true pugs (eg its not you + 1 buddy + 1 random) using an automatch system. Teams play on the same team but against other teams using an automatch system. The closest chance pugs had for this died with skirmish mode (which has been removed). And perhaps we'll see something for teams in 1.3 clan wars. We'd obviously need 2 ladders... a PUG and a Premade. I doubt any of this is coming any time soon though, but I digress.