I wasn't trying to deny the existence of these people, and I imagine its a similar feeling to how I feel in my community, but I'd be willing to bet the "judgement" you feel is a lot less severe than that of those who attack christians. Let me put it this way: Somebody who believes their entire life in Jesus Christ and Christianity and genuinely tries to be a good person gets told things like:Saying that people who use the Bible to attack people aren't Real Christians and don't represent Christian values doesn't change the fact that those people exist in some capacity.
There have been many phases in my life where I simply felt uncomfortable sharing that fact that I was atheist in my community, because I'd be shunned or attcked for being immoral off the bat. I currently live in the Bible Belt and used to live in Utah, and not everyone takes such an academic view of Christianity.
They may not be Christians to you, but their values are shared and validated by their communities. You can't ignore that.
"Most modern Christians only follow the parts of the bible that line up with their own personal agendas."
"your "belief" is nothing but mere blackmail"
"you believe in a vile and hateful book"
They're also told by many atheists or agnostics what they as Christians believe in like "christians believe that all gays will go to hell" etc. and that puts them at a moral disadvantage from the beginning.
All of these examples came from this thread on the internet on a meaningless Pokemon forum and its only worse in real life when you factor in judgement of Christian values (controversial topic of abortion, for example)
These things are regular things that Christians hear all the time even from people who may be not offensive or bad people in general. I guarantee things like this are not said to non-religious people because their "faith" can't be attacked because they just don't have one. And there's nothing wrong with that, but there isn't something to be attacked. Some judgement from people who find you "immoral" (who should treat you like any other person) pales in comparison to the belittlement of many people which Christianity is such an important part of their life.