Really, honestly, seriously. Have you even tried to consider it could be that way around? Occam's razor suggests -- no, it screams! -- that he killed himself:
* People get desperate and kill themselves in some situations. McAfee was in a typical such situation.
* Having killed himself -- or not, as some would have it -- at the moment McAfee is big news. People (such as yourself) are (literally) screeching bloody murder. If there is anything to find, investigative journalists now have lots of incentive to look for it. If he'd just been extradited, probably no one would have cared; there might have been a few short articles noting the fact, and that would be that. Wouldn't it be stupid, then, to kill him since that would only attract all this attention (that you and I are lavishing on it)? How plausible is it that any actor that has the resources to have someone "whacked" is that stupid?
* Lots of people (you possibly among them?) have suggested that he was killed because "they wanted him silenced". I have asked a few what, exactly he is supposed to have had on anyone that would warrant "silencing" him. So far nobody has had any suggestions. Do you?
So, yeah, it does indeed look like some are doing their best to avoid facing the truth: You all who see a conspiracy here.