Some form of apostacy has existed among Muslims. Initially it was nifaaq. The apostates have either hidden it, or at least moderated it if they were living in Muslim societies. Many such apostates even came back to Islam as their end approached.
This does not apply to apostates living in non-Muslim societies. Most there had taken off quietly, falling into sin, and leaving the question of faith unanswered. This is changing now, and a virulent aggressive form of apostacy is being seen, which actively seeks to convert Muslims away from Islam. In addition, there are reports of large numbers of Muslims being enticed away. How far these are true, I cannot say, but some must be happening, particularly in Africa and in the West.
For some time, as you may have concluded from my posts, I have been reading on and researching unIslamic behavior that may be leading to declarations or acts of apostacy from Islam. Here are some of my thoughts. There may be more. I would like others to suggest what other reasons come to their minds. Then maybe we can figure out ways to fight this.
Please also post any links that may be of interest in this regard, particularly if someone has actually researched or some alim has answered this question.
Causes of apostacy from Islam:
1) Belief that Allah is non-loving, while the Christian God is loving, having sacrificed his only begotten son for humanity.
2) Belief that Islam is stern, does not allow fun
3) Love for and expectations of marriage to a non-Muslim man
4) Perceived discrimination of expectations of tolerable behavior from male and female children
5) Peer pressure
6) desire to taste alcohol, dance, gamble, eat non-zabeeha meat etc.
7) tendency in the teens to peel off dress
A contemporary desire to avoid conflicts by letting things be, to let everyone believe in what they want without any proselytizing, as this leads to conflicts
9) Hotheadedness and rigidity among Muslims
10) Moral restrictions at home, and consequent rebellion against them
11) Too much strictness, and harshness in punishment for unIslamic behavior. This may include denial of home entertainment like watching TV
12) Too much laxity at home. Sometimes this takes the form of hiding from the stricter parent any behavior that is unIslamic, or protecting the child from a little punishment to drive home the message. Usually it is the mother who does this hiding
13) A clash of values and actual living. For example, a career in movies, singing, or modeling may be considered inappropriate, but movies, pop songs videos, model shows, beauty contests, female swimming or tennis, etc. would be eagerly watched at home by those wanting to enforce these values
14) Another example is being integrated in the interest-bearing economic system, like working in a bank, calculating interest as an accountant or financial consultant, etc. but ruling out the showing of skin or beauty