Personally I'm very impressed with the artistry in the Spiderweb products I've tried, but am also very interested in efforts to raise the bar still higher. I just don't understand what I detect as a continuing thread of resentment at Jeff Vogel. Our hobby is his business. He must be honored to have such a discerning core of afficionados, but I doubt that hard core scenario designers number in the thousands, and so I doubt Spiderweb can live on their shareware fees alone.
On the original topic, a point from my experience as a pen-and-paper RPG gamemaster, which might perhaps carry over to BoA scenarios:
You can sometimes go one better than just making sure that an answer exists for every Why, and revealing the answers in the course of the game. You can reward the players, with power and success in game terms, for assuming that everything really does make sense even when it doesn't seem to. You can make it a winning strategy for players to ask Why, come up with answers, and act upon them. So the Good Wizard does hire the neophyte party to attack Lord Evilmancy, without any good explanation for why he didn't look for more experienced heroes ... but if the players regard this as a mystery and try to investigate it, they will discover great things. If you can pull something like this off, you are doing something which is truly a union of story and game that is more than either alone, in that major plot twists will be driven by player initiative.
The hard part is that the extra oomph comes from leaving it up to the players to perceive the inconsistencies as mysteries, rather then poking them in the face with immediate dialogue boxes. And it's never going to seem worthwhile to players to take the trouble to think this way, if their experience indicates that there will be inconsistencies in the scenario due to mere designer incompetence. In a pen-and-paper campaign, I could undertake in advance to improvise remedies for any inadvertent inconsistencies, so players had insurance against giving my world more credit than it deserved. In a self-contained product like a BoA scenario this would obviously be a lot harder. But perhaps if you do well enough in following Drakefyre's rules, you can eventually earn the right to bend them to additional effect.