Few things to say about this.
On some levels I agree with the designers. The points, when I first played were very ambiguous, especially C (the bottom level was confusing). Once you get to know the map, the problem is resolved, but there existed a problem nonetheless.
I also agree about the team splitting. Yes, Gravel Pit splits teams, but there's a certain degree of cohesion to which it happens. I don't know how or why but the way Glacier functions, I feel the teams can split on a much more confused basis. If I was to compare it to liquids, Gravel Pit is like throwing honey down on the ground, while Glacier is like water (this would be a more extreme example).
Furthermore, they do make a valid point about C. I will return to what I said about the A/B split with regards to cohesion. C is a pretty cumbersome point to get to, there are a lot of entrances through radically different and distantly connected portions of the map. In Gravel Pit the attackers team can always be found in one of 3 places, while in Glacier, it's not always obvious where they are, and often the team isn't together.
Finally, how the hell did you get Valve testing you lucky sob :O :O :O