Well just because muslims missunderstand certain aspects of christianity wich are allowed within it's borders... then we don't have to completly abolish them just because they -or whoever missunderstands that- do not get that.
the funny thing is that the christians who judges other denominations of being flawed are the ones that think that they have the perfect christian doctrine... if you really look at the denominations from a bigger viewpoint instead of a narrow one, you'd see that what all these demoninations have in common is the gospel and the spread of it, all bow down to Christ and Christ is the head of all denomations making them all one big church, one big brotherhood.
if any man (you or another) missunderstands certain aspects of certain denominations, then learn it and make it so that he or she understands it, instead of being ashamed because you think the critics are correct without having the viewpoint of the denomination's explanation for it.