Earlier quoted context omitted.
Why would anyone want him dead? I don't think anyone cared about him that much.
If people had reason to kill him, it would likely be that he knew scandalous information. The public wouldn't really know that people cared about him or what that information was. I have no idea if McAfee had such knowledge, but "I don't know any reason why someone would kill him" doesn't mean much.
Whatever McAfee would "reveal" would just be his word. Which isn't great. Unless he knows how to obtain evidence of things, what he "knows" is just rambling.
Movies have instilled in us this notion that simply knowing something is good enough. It's not. Let's pretend for a second that McAfee knew that certain public figures were, without a doubt, 100%, Satanic pedophile lizard people or whatever the flavor of the month panic is.
If his only proof of this is that he saw Person X devour a live baby while molesting children in the basement of a pizza parlor, it's kind of meaningless. It's not much better than just saying you know it because you believe it really strongly.
The information he would have to know would be specific to uncover something in a way that people could actually act on that information.
Otherwise, it's like what Bill Murray whispered in my ear after he painted my house last night, "No one will ever believe you".