Obviously the full concept of the IT has not been conveyed to those who so easily dismiss it. Of course IT invalidates the other endings; it would have been the springboard to meaningful DLC that continued the story to a conclusion that had a chance of making sense.
Oh, by the way, that is how you improve the ending. Not really sure what the grand mystery for the deep thinkers is here.
Want to play a game of ME3MP?
Qui-Gon_Glenn on the software of which we shall not name.... add me and the enemy shall fall in chunks of crimson salsa