1. So the moment someone disagrees heavily what what you consider to be canon it must mean that it must be those darn NMA'ers? Seriously?
2. And where do you get this "even split"? As far as I can remember whenever the discussion of it's canoninity(???) comes up most people agree that it is not to be considered canon.
I don't have time right now but I found a bunch of threads searching for "Mothership Zeta canon" in Fallout 3's forums and I'll read up on them later to refresh my memory. But hey, if you want to you can always open up a poll thread which asks the simple question as to whether it is to be considered canon or not and then let the discussion flow as it goes on.
3a. Okay so because there are consistent 'easter eggs' about "aliens" they should be considered canon? So if Doctor Who easter eggs had been consistent then it must mean that The Doctor is floating around in Fallout? Or if Godzilla footprints was found at least once in each game as easter eggs then it means that Godzilla is actually walking around in the wasteland?
3b. What? You mean easter eggs? Yeah, a Wild Wasteland trait is the only way to trigger them, at all. Which means it is not to be taken seriously, hence the name "Wild Wasteland" and it's goofy graphic.
3c. But they aren't always the same, so they aren't consistent. In Fallout 1 the crashed UFO mentions it is part of the US military and the corpses are those of people who have suffered sideeffects from Mentats. In Fallout 2 the crashed "UFO" is a pod from Star Trek and in Fallout 3 it is neither US military nor is it a Star Trek pod but rather a more alien looking saucer with a green grey beside it. None of this is consistent.
4. Here's the bottom line, Bethesda are secretive and are bloody awful at clearing up what lore is official and what isn't so when something as controversial as this comes up we must think about whether or not if fits Fallout, for what reason the DLC was developed, how the fans reacted to it and whether or not it has a future in Fallout. We've gone through threads about MZ before and nothing good comes out of accepting it as canon. And guess what, if the fans vehemently oppose the idea of it being canon there is a greater chance that Bethesda will consider it non-canon as well.
But quite frankly, I don't care if you consider them canon, I won't. It might seem very arrogant of me but there are some [censored] ups that the developers sometimes make which I will refuse to consider canon because just cause something is in a game doesn't mean it is automatically canon until stated otherwise. Sometimes we as fans must take the stand to look at a topic and decide whether or not it fits.
Some other things I refuse to consider canon; That doctor in Underworld saying radiation has anything to do with ghouls turning feral, Lesko using FEV to create fire-ants and fire-ants magically appearing in the Mojave when supposedly Lesko created them.