Well, Spartans may not have a sex drive, but since when has ANY ODST or Marine been able to "do it" while serving in the UNSC? The answer is zero. No soldier has ever "done it" while in service, so why don't we drop that card now. Ok, so why does everyone say Spartans are not human? Unless you're a stupid moron, Spartans are Homo sapiens just like the rest of the UNSC, though alterd to make them Supersoldiers. And I don't get how ODSTs are more badass than Spartans. Oh wow, falling from orbit in a HEV pod makes you so hardcore. Guess what, Chief did it too. Besides, in Halo 3, Chief fell from orbit with NO HEV, and still kicked Covenant butt. (as well as the Marines and ODSTs)
I feel the main reason why people like ODSTs better than Spartans are for the following reasons:
1. Lack of sex drive (as if they get any action anyway).
2. They want to be more "human" but does anyone remember that all UNSC service members have the neural transplant in the back of their skull, so in a slim way, would make them cyborgs as well.
3. Spartans were over glorified, and the latter wanted to be know just as regualr Spec-ops soldiers.
4. Everything in Halo was about a Spartan, John-117, and feel that the other soldiers deserve some respect and fame, though I'm sure if Halo was about ODSTs mainly, then most people would want to be Spartans.
5. My last one, the whole entire cold-blooded, killing machine, unloving soldiers known as Spartans. Please tell me in any book or game, where it has been mentioned that Spartans are not as caring as normal humans. I would like some REAL evidence where it mentioned that Spartans don't care for humanity, other soldiers and the like.
All in all, it comes down to which soldier suits you the best. I don't understand how ODSTs are any better than the Spartans or Marines in anyway, (besides the amor and enhancements) as I said before, their all fighting for the same reason, so I don't see why we need to prove who is better than who. No one is better than the other. We're on the same side, everyone works as a team. I don't get why some people can't accept that.