The clever chaps at ResidualVM
(the 3D sister to ScummVM
) have finally discovered the reason for the missing dialogue at the end of Grim Fandango. As it turns out it wasn't a design choice, it was a simple bug...
A bug so buried that apparently not even Tim Schafer was aware of its existence
"I had no idea that there was a bug in Grim that caused a critical dialog not to play! :O! But these guys fixed it."
The bug is now fixed for players using the latest version of ResidualVM to play Grim Fandango.
You can get ResidualVM for free here: http://www.residualvm.org