While on the surface I can see your points I think your perhaps negative connotations of the themes in Halo are largely due to your lack of knowledge about the franchise. You're right the Spartan program is pure facist escapism. Spartan II's are kidnapped at childhood and then trained and augmented only to be sent into missions where most die. Finally they are ironically abandoned as a project because despite being exactly what they should be there aren't enough of them to turn the tide of war, cheaper, more expendable Spartan III's are created to better serve the whole.
Despite the player being thrust into these boots as the protagonist (or ones' like them in their less abused brethren the ODST) Spartans aren't liked by the rest of humanity, feared, pitied, used and perhaps heroes of the moment the authors of Halo take pains to subtly point out that their inception is a tragic one borne (worse still) in the midst of an internal human struggle not the war with the Covenant.
As for the diverse alien races being the enemy while the uniform protagonists being the heroes I think you're missing the roots of the game in Marathon and the general FPS / gaming enemies rules. Simply put if you have more than one enemy the little ones are numerous and weak the big ones are large and powerful and the medium ones' are wily and smart. Giving them bright colours and distinctive looks is about allowing the player to identify threat and pick targets accordingly.
It is of course possible to argue that all games that have multiple enemies of differing shapes and sizes and form a 'jabbering horde' show a certain amount of disdain for mixed communities as an underlying theme and that all similar looking human armed forces sent to destroy or are besieged by said forces represent the stalwart but ultimately stagnant human species but then I think you'd have to look at media as a whole and not gaming or a game in particular to make your points valid as an exposure of a series of prejudices underlying narrative creation.
Additionally I always found the breadth of Halos' human forces to be fairly wide, especially if you listen to the thousands of lines of incidental dialogue, of course you'd have to play the game a lot to see that.
I think what you have is a dislike for Halo based on an initial impression and despite dipping your toes into Reach (which isn't the best game for character or anything in the single player campaign when compared to Halo 1 or ODST) you've found a bland underbelly of repititious firefights, ham-fisted dialogue and dubious narrative direction. This is a fair assessment, largely because Bungies' swan song was about fighting in space for a while and the best damned customisable, recordable and fun multiplayer setup you could have (at least that's how the fans see it I'm a mouse and keyboard person myself so the multiplayer doesn't appeal to me that much :S).
I agree that the elements you describe are for all intents and purposes able to be interpreted as you have however Halo is about the vast and far reaching universe not the campaign and not the single player. Listen to I love bees, read Contact Harvest that's where the themes of Halo really lie. The Halo games are what Bungie makes money doing, the Halo universe, its depth and complexity are what Bungie loves telling. An ill-fated ownership by Micro$oft and exclusivity to XBOX left them with a juggernaut they couldn't control but had to service; multiplayer. Leading to diminishing returns on the narrative of the campaign which eventually moved to books as a medium of getting the big picture out to fans.
You basically came in at the end of the franchise and looked around and said: "Meh" which is entirely understandable but imagine that a few years ago there are probably people who did that to Star Wars Episode 3 and have since decided not to watch 4, 5 and 6 not read the extended universe novels and abandon Star Wars as a franchise because Episode 3 had a preposterous and funny Vader ending, most people would say: "Don't be so short-sighted, give it a chance."
So Bob:
http://www.ilovebees.com/humptydumpty.html
Listen to them, if you get to the end and like what you heard, read:
http://www.amazon.com/Halo-Contact-Harvest-Joseph-Staten/dp/0765354713/ref=sr_1_1?ie=UTF8&qid=1289431918&sr=8-1
I know, I know, I'm hammering it home a little hard here but you just published a video that likened Halo and perhaps games in general to being anti-multicultural and a little bit fascist, I don't think I'm way off base if, loving WW2 and ancient history and Halo as much as I do, I try and educate you to why I think you might be wrong. The first link only requires you to listen to what is ostensibly a long radio play. If you get stuck in and still think your views are spot on, by all means stand by them.
Prefacing that video with the idea you're not well versed in Halo has set you up for some headaches and the bonus for you is that if you get stuck in and change your mind you're all the braver for re-evaluating and seriously, how many people on the internet get to come back from a faux pas of any description, intentional or not?
