Nonsense.
I mean, that's the real definition of atheism.
Wow. Okay, let me get comfortable, this is going to be mind blowing.
The idea of atheism is underpinned by a strong idea of self-determination. Which is fine, there are agnostics, and even theists that don't particularly like an all-powerful God running their lives. This position is called maltheism, and is perfectly fine. It's OKAY to be mad at God for screwing your life.
Yeah, I'd be interested in how you are defining agnosticism, but an agnostic who hates God appears to be a theist. As would anyone describing themselves as an atheist who hates God. It happens, no doubt. People mislabel themselves for the damndest reasons.
I don't think it's okay to lie, and say you don't believe in something when you do.
I dunno. I don't have an issue with any Jews who lied to the Nazis about their cultural and religious heritage during WW2. I realise you're trying to draw some sort of long bow to suggest every atheist on earth is a liar, but rather than finding that personally affronting, as well as ridiculous, I just figured I'd read the rest of your post and see if it held much water.
The unfortunate part of this is that... they all secretly believe in God/gods/something like that on some level and are in deep denial, so they go to logical stretches and absurdities versus just stop sweating it.
Wait a moment. Your arguing that atheists believe in something? Of course they do. Who the heck survives without any beliefs? This seems very strawman-ish.
Let me give you an example: They spend an excess of their time mocking theists and religious types (especially Christians, but other groups too), and trying to discredit the idea of an afterlife. The fact of the matter is, is they simply did not believe in an afterlife and did not believe in God, they wouldn't argue with anyone. They would be either agnostic in the minor case, or religiously indifferent in the major case. A person who does not believe in something, simply does not believe in it. I don't believe in aliens, for instance. I'm not sure I go around telling people "Aliens don't exist! Listen everyone, don't believe in aliens, they aren't real. I know you think there's flying saucers, but there's not!" Something about protesting too much.
More like something about privilege...
So, luckily for me, I live in Australia. I've also lived in New Zealand, and have spent time in Sweden. All three have sizeable Christian populations, but are largely secular countries. Atheism isn't exactly a hot button topic here, and most people wouldn't bother talking about it much.
Not everywhere is quite so lucky though.
In 13 countries, a death penalty can be applied, for example.
In 7 American states, there are still constitutional clauses banning atheists from holding public office. (luckily unenforceable as they contravene Federal Law)
Atheists are commonly reckoned as untrustworthy.
Creationism continues to be pushed into state schools via the science curriculum.
Even in my country, until recently, marriage equality was fought against due to religious belief (almost solely).
Ultimately, you don't get to have a say in what atheists are interested in, and want to speak about. You can disagree as you see fit...that is the entire premise of free speech. If it makes you feel any better, I don't get a say in what atheists are interested in and want to speak about either, despite being an atheist. Some of the atheist 'beliefs' that get espoused are cringe-worthy, ridiculous, and completely misrepresent me as a person. ('Brights', anyone???)
To belabour your example, you might not believe in UFOs, but you might find the topic quite interesting if 3 billion of your fellow humans did, and it started impacting on government policy, teaching curriculum, etc.
Human beings only get upset about something if it is personally meaningful to them.
Religion is entirely meaningful, and people's beliefs in God are entirely meaningful. They impact, in very concrete ways, the world around me.
Even looking at religion as a positive force, how can you consider something that motivates that many people to be meaningless in the lives of the people around them?
My mother and sister are both Christian. My dad is more the sort of agnostic you speak of. I'm an atheist. I see no reason to apologise, nor hide, nor lie about my beliefs, or lack thereof.
So, let's look at this. They, far from not believing in God, either actively hate God or are afraid of some sort of rulership over their lives. (Ironically, they choose way worse rulers to their own life than some being who mainly deals in coincidence) Likewise, many atheists choose to disbelieve in Afterlife as a whole, because they fear that God will send them to Hell for their pathetically minor sins.
I like to picture you strutting on a stage, preaching this to the converted. For surely that can be the only intended audience for such self-fulfilling logic?
You state your argument as fact without evidence, then proceed to nod along with yourself. It's mostly amusing, but there is a little bit of caricature there, intentional or not.
There's no proof there even is a Hell. The Bible refers to an outer darkness. But... it's more like Heaven's suburb, a place where you are near God, but not able to be in God's presence. In fact, the state of Hell, which is defined as "eternal separation from God" not eternal damnation, is something that is not even a thing.
You are now arguing that atheists actually believe in Hell, and that you, a believer, knows Hell isn't even a thing. And this makes sense to you?
In essence, atheism is deep denial about one's own fears and insecurities couched in pseudo-scientific thinking, much more often than it is a legitimate indifference to religion.
I'm not indifferent to religion at all. I just don't believe God exists.
*shrugs*
You're really overcomplicating things.