A "phobia" is a fear, I don't think most people that disagree with Christian based systems actually "fear" it, it is just a result of what has come before and since because of those systems. I have said this before but Christian based systems were responsible in the west for the suppression of science and probably set it back several hundred years or more because science seems to have been a threat to their social and political control and religions made up some of the earliest political systems, not to mention the complete destruction of entire cultures and religions, the witch hunts etc. in the name of those same systems. More recently in this country (in the 1980s) that there were a large number of people that actually believed that there was a huge "satanic" conspiracy that was involved in ritual murders, child molestation etc. that reached to the very tops of society- we could pass this off as just a few nut jobs with a need to believe in conspiracies but there were a large number of innocent people whose lives were affected through allegations of SRAs (Satanic Ritual Abuse) in courtrooms across America during that time, this wasn't helped by some in the psychological community that went with the recovered memory theory, although these "memories" were often coached ones, innocent people still went to jail because of fear of "satan" brought on by the same culture that was created by the belief in him. The book "Michelle Remembers" seems to have been a huge contributing factor to that movement, but it has since been virtually debunked by actual investigation. It wasn't until later when Kenneth V. Lanning of the F.B.I. made his report on SRAs in 1992 that some of this receded. Then we have music album and book burnings etc. done in the name of good by these same people that believed "satan" was destroying America, (much like the Nazi book burnings in Germany) I remember being invited to one of these when I was in Jr. High School by a friend but I didn't go ( I actually told him to give them to me because most were good albums). Of course those things don't represent Christs teachings from what I understand, and don't necessarily represent the whole, but the fact remains that this wasn't just a few nut jobs, it was a lot- and the law and innocent lives were negatively affected by it.
I have no problem with Christianity itself, what Christ actually taught seems pretty benign, limitless love, forgiveness,turning the other cheek etc. but it isn't for me, What I do have a problem with is systems (no matter the name) that have been mis-used to control and manipulate others to gain and keep power and punish the innocent or merely those that disagreed in name of "good" while actually the few that pulled the strings manipulated them for their own gain .
(My personal opinion) I have heard it said that it was actually "satan" that caused these things or was responsible for the "evil" that was done in the name of "good" to confuse human-animal kind but I see this as only an excuse for not confronting and acknowledging the darker aspects of our humanity which we all possess. I feel that the belief in the external causes us to forget the internal, and the internal is what actually drives us. There are no gods, goddesses, devils etc that cause us to do good or evil, I see these as ways to describe aspects of ourselves that cannot be understood and causes imbalance. I feel that acknowledging our dark and light aspects and working towards the understanding of ourselves and our true natures is crucial to keeping the balance within ourselves, which will affect the external through our actions.