If I said, "What Jews believe is ridiculous!" would that be racist?Probably, yes.
If that is your definitions of anti-antisemitism most atheists are anti-semites (as the obvious connotation of "Jew" here is "religious Jew" not "ethnic Jew"), which I cannot imagine you really believe.
IMO Harris and Maher are complete asses when it comes to Islam; I'd even go so far as to call them islamophobic. I don't think that makes them racist. Islamophobia and anti-Arab/brown people racism definitely overlap, but they are not synonymous, in the same way that transphobia and homophobia overlap but can exist independent of each other.
I think the belief that an angel came to a middle aged merchant in the 7th century and delivered to him the Final Revelation is ridiculous, while simultaneously I am not threatened by people who hold that belief nor do I believe them to be bad people. Plenty of atheists hold views like this, being intellectually critical of religion without being bigoted towards believers.
But there are certainly plenty of atheists that are like self-righteous teetolators that never shut up about how evil alcohol is, never mind that most people who drink know it isn't good for them. You don't want to waste your time at church? Great! Me either, but for fucks sake there are way more dangerous things in the world than religion, which is far more likely to be used to excuse/justify shitty things than to actually cause it. This is where people like Maher and Harris loose me. It's as if some people are wired to need some kind of Enemy to hate, a Great Threat that must be defended against above all others. While I have my issues with religions, particularly cults like the COS, in the grand scheme of things there are bigger fish to fry.
TLDR; You can be critical of religion without being bigoted against believers; you can be bigoted against believers without being racist.