Let me answer this question in a few ways.
First, I am not certain if atheists attack Christianity the most. I think you are probably right, but it would be nice to see some statistics.
Second, it makes sense that atheists attack Christianity most, because by and large Christianity is a Western religion (at least of late). More importantly, the West believes in the freedom of expression. So, Christianity which has shaped the West allows for people to criticize it. In other places, like the Middle East, you cannot attack Islam. If you do, it might be the last thing that you do literally.
Third, Christianity makes some bold claim. So, in some ways, it sets itself up for criticism.
hameye shoma kafer hastid.chera mosalman nemishavid?
In last two to three months, specially before the Christmas Day, there were various remarks made against Christianity in a web site. I saw as if a war was going in between the believers as they call 'Theist' and 'Atheist', the non believers. What I believe that his is due to the lose of sanctity of the religion. I do remember the poem by W B Yeats the "Second Coming" where he predicted that its time for second coming of Son of God and sanctify it again. He has given a contrast of Felcon and Felconer and symbolises with a gyre.
Science has progressed a lot to give us everything for food, comfort, to shed away fear and even taught us how to create new things for us. All these inventions are related to our senses and therefore some people go to call it a Sensate Civilisation. We are now quite absobed in the material world which provide us our basic amenities and these are in front of us. On the other hand God on whom we believe is invisible and people think He is imaginary of some people to rule and exploit others in the name of religion.
Now a days, we have lost our past culture and have a blended of all. As a result we have lost morality. We have divided us in so many groups like-ethenic, religious, economic, political and so on. People give more importance to them in which he has much interests. For these reasons, people have no time to think of an invisible authority.
In this post modern era as we call, there is no room for Heaven and Hell, wrong or right, sin and piousness but we talk of common sense and some are giving importance in the Evolution Theory that Man has evolved from Ape.
We look at everything with the eyes of science and it is a matter of great grief that the range of the eyes of science is by and large increasing but yet not attained to see the mystery of "what is life". Why do we die? The material body remains there but unmoved.
Its true that Christianity is in rise in other places but dying in the country emerged based on it. Because they have lost morality whereas in other countries morality still exists.
I admit Christianity has lost its way over the years, ever since people have become secular or Liberal. I think that there is alot that is not mentioned in our History books and Science books. Maybe there is certain things that we should think about considering as History. I know that Science and Religion will one day get along, but first we need to let both religion(the unseen) and Science(what is seen) to finally progress. I believe faith in any god is just as important as science. Atheists claim to attack all faiths, yet right now in many parts of the world Christianity is being persecuted. One atheist leader claimed that "the world should eradicate all of christianity. I think this is just as bad as communism which killed millions in the name of no god. I think that Christianity and the other monotheistic faiths should back eachother up because in Europe much of it is intolerant of religion. In many Eurpean countries you can't pray in the streets if muslim or christian. Much of Europe has becom secular, yet studies have been done that europe has the lowest attendence rate in the world. the people that do go to church are the mere old and dying ever since the birth rate has fallen for christians and others have greatly declined as well. I see much f europe is hopeless as nobody is allowed to confess that they believe in god. In europe thew younger generation won't go to church. I believe that Christianity is dying in europe, but is on the rise in nine of the most unexpected places:
2) Southern Africa and beyond
5) South Korea
7) Phillipines (many mujahdeen islamic soldiers even)
8) Greece(due to economic downtoll)
9) Iran (might sound crazy, but the persecuted are growing in the underground church.)
Well alot of stheists blame Christianity is the reason we never progressed in the dark ages. They also beileve that since christianity had a reformation its our mistakes for the worlds uneven problems. They protest all because of a nativity scene or just because people are praying in public, but you never here people complain about other minority faiths, but I can say the statistics are in a way already out. I know many muslims and Jews that respect christians, but atheists blame christianity and say questions like if god is real then why would he create someone that died for our sins, why didn't he just get up if he's god? Well that to me is insulting.