Well, as much as I like to see things explained in the story, I can really agree with you here.
For one, if all pieces of the puzzle are fitted together, then fans don't have any room to try to make their own imaginary pieces.
I'm glad that many members are exstatic about getting their ideas cannonized, but really.
Without any mystery in the story, that leaves less of a workspace for Epics or MoCs or anything creative.
I mean, I think that the Hagah and the Mangai are the main two Toa teams who are MoCed or Epiced or Short Storied about on BZP.
With Kualus, he'll make an appearance in my Epic as a Ko-Matoran who resides on Thārlax Påzil, a peninsula that is dominated by only avian Rahi.
If all the origins of the Hagah were explained, I couldn't do this.
So I applaud Greg, in the name of creativity.
-Kohilå