If you have been crying since you may want to get your eyes checked! XD
I am fairly certain that from the characters' point of view Matoro was not revived simply because there was nothing left of him and no method by which they could even try reviving him. The Mask of Life can do a lot of things, but the revivals we have seen in story have either been done with a body part handy (such as when Takutanuva revives Jaller via his mask, or when Mavrah's corpse was recently revealed to have been taken to the Red Star), or in the case of Hydraxon it was not a "true" revival so much as a transformation of a different being. Matoro's spirit was likely broken down along with his body when the life energy was spent, so that it's impossible to revive him.
Maybe the mask could create a copy of him like it did of Hydraxon, but the potential storage spaces for such a copy are offline (the Great Spirit robot is broken) and the Mask of Life cannot be used by common beings. I also I imagine having a clone of Matoro would not feel the same. Mata Nui has chosen to go dormant, and I'm not sure how aware he was of Matoro's role in his own revival. Being able to resurrect Matoro at all without sacrificing the life force of another being is likely impossible.
From a story writer's standpoint, I don't think Matoro will ever be revived. His role has been fulfilled, and it was fulfilled beautifully. Bringing him back just for the sake of bringing him back would not sit well with me; and I believe Greg has expressed a similar sentiment when asked about the potential for Matoro's return.
If you want to think of it poetically, Matoro kind of lives on as part of Mata Nui.
^ All correct I believe (until Bonesiii gets here blasts us with his bio-canon ), except I don't quite know what you mean by "the potential storage spaces for such a copy". I did wonder where the Ignika got the information to turn Dekar into a Hydraxon 2.0, was that from somewhere in the MU?
But yeah, your basic answer is that Matoro cannot be truly revived, because his body was completely destroyed, turned to pure life energy. The Ignika could turn someone into a Matoro clone that for all intents and purposes would behave like the real Matoro, but it wouldn't be the same.
He's actually among one of the few MU (Matoran Universe) characters that cannot be revived by the Red Star or otherwise, since there is not physical remainder of him.
And welcome to BZP! I came here last year, a while after Bionicle's end too
Edited by NuvaTube, Jan 02 2014 - 12:59 PM.