He hates the non-Plus atheists. ("Dictionary Atheists. Boy, I really do hate these guys. You’ve got a discussion going, talking about why you’re an atheist ... and some smug wanker comes along and announces that “Atheism means you lack a belief in gods. Nothing more. Quit trying to add meaning to the term.”" -- source)

I don't think he's saying he hates all non-Plus atheists (whatever that means) here. It seems to me he's saying that he hates atheists who don't see atheism as a part of a broader network of commitments or values, or resist the idea that it should be seen as such. He goes on to say, "there is more to my atheism than simple denial of one claim; it’s actually based on a scientific attitude that values evidence and reason, that rejects claims resting solely on authority, and that encourages deeper exploration of the world".

That actually seems like a pretty reasonable position to me (although "hate" is admittedly a strong word to use in this context). If indeed there are people who see atheism as fundamentally disconnected from general-purpose rationalism, or who don't see the promotion of atheism as a mere corollary of the promotion of a general rationalist worldview, or who object to making the atheist movement about rationality and science rather than mere disbelief in god, then I do think those people are wrong.

It does seem odd to me that there would be a significant number of atheists who adopt this kind of view, though, so maybe Myers is attacking a strawman here.