Why local churches don't accept Muslim believers

People are surprised when I tell them that most local churches (including many evangelical ones) don't accept Muslim-background believers (MBB's) into their fellowships. A nice list is provided in Carol Walker's essay on women in the Muslim mission field, which is a good read in itself:

Local Church response to a convert from Islam is often one of non-acceptance. This may be due to

* Jealousy (eg., poor or needy church members looking to mission workers for attention or money.)
* Fear. This may be of the newcomer, with the fear that they are infiltrating in order to find grounds to betray and bring some kind of action against the church. In this case the newcomer would find himself or herself mistrusted and unwelcome. Alternatively, the fear may be that family members of the newcomer, or perhaps the security services or some other group, will blame the church for the individual's conversion and take some kind of violent action against it.
* Suspicion. They've been cheated before; there have been conmen who have claimed to be needy converts but who were later discovered to be wilily members of Christian families.
* The presence of someone different may simply threaten the status quo
* It is un-cultural to change faith communities and leave the patterns of the family home; someone who does so can even be seen by members of the Christian community to be violating a deep rooted belief about what is right practice, and to be breaking the order that God has made. Much pervading thought accepts the idea that God ordained people to their particular religious communities and that is how things should be left.