"Pushing some of the more interesting content to an earlier point in the game, where more gamers were likely to experience it, was also considered"
They really shouldn't. If 80% of the people run out of reasons to continue playing then removing the cool stuff from later in the game will only give EVEN LESS incentive to keep playing as you've had all the good stuff I the start, its filler after that.
People quit playing before the end as the gameplay gets worse.
Sorry to say this, but this is down to the developers. They MUST NOT blow their wad in the first few levels, they have to steadily give more and more, always with more tantalising in the next part and upping the ante to a final crescendo.