Looking at texts from a Pope or Patriarch is not how anthropologists determine whether or not a practice is done for religious piety.
The statement of the Pope is, so far in this thread, the only
reliable indication given of the Coptic Orthodox religious
attitude to female circumcusion.
I read the document you linked to beforehand; it presents not a shred of evidence that any Coptic Christian practices female circumcision out of religious piety, let alone that it is a popular practice amongst Coptic Christians motivated by religious piety.
What is problematic with the methodology of the referenced NGOs and other organizations? Unless you can show that their numbers are way off or the methodology that they have been using is dramatically flawed, their findings are of a nearly ubiquitous practice.
There are a number of problems with the document you referenced us to, and even more with your uncritical interpretation of it. Let’s take a look at the only statement made in that entire document that touches on the question of the religious attitude of Coptic Christians to female circumcision:
Moreover, many Egyptians believe that this is an important part of maintaining female chastity, which is part of religious tradition.
This is a very vague statement, and it is practically useless to us for a number of reasons.
1) The statement indicates that female chastity is part of religious tradition; it thereby implicitly suggests that religious tradition was the motivation behind those who practice/advocate female circumcision for the purpose of maintaining female chastity, but that is just conjecture. As I’ve already noted, people may want to maintain female chastity for other reasons, such as to avoid social scandal. The document itself goes on to say: "One of the main factors behind the persistence of the practice is its social significance for females. In communities where it is practiced, a woman achieves recognition mainly through marriage and child bearing and many families refuse to accept as a marriage partner, a woman who has not undergone the procedure." Ultimately, therefore, there is no statistical or otherwise concrete data whatsoever presented with regard to the religious attitude of those who practice/advocate female circumcision; only a speculative suggestion as to how to interpret one of the results of the survey. As for the problems with the survey itself and problems with the generalisation you've made in response to the survey (i.e. that female circumcision is an expression of popular piety amongst Copts):
2) How many of the surveyed Egyptians were Coptic Christians? The document gives absolutely no indication whatsoever of how many Coptic Christians participated in the survey. Nice way to make generalisations about popular piety amongst Coptic Christians, especially in light of points 3) – 7) below:
3) We are told that the sample size was roughly 15, 000. Nice way to make a generalisation regarding a community of over 10 million Copts, especially given points 1)-2) and 4)-7).
4) The document suggests that more than 91% of the Egyptians surveyed who do practice/advocate female circumcision do so for reasons that have nothing to with maintaining female chastity. So less than 10% of a weak 15, 000 sample of Egyptians advocate female circumcision to maintain female chastity for reasons that are most likely social and cultural than religious. Nice way to draw generalisation regarding popular piety amongst Copts, especially given points 1)-2), and 5)-7).
5) We are given no information about the circumstances under which the relevant information was acquired. Were these ladies’ husband’s present? Was it face-to-face? Was it conducted publically? Were they required to disclose personal information? etc.
6) We are given no information about the nature of the survey itself: did it allow for open-ended answers (e.g. “Do you practice/advocate female circumcision, and if so why?) or were participants told to select between a selection of pre-determined answers which could potentially have manipulated the answers given?
7) We are given no information about the participants in the survey. Were they randomly selected across the whole nation? Were they chosen specifically from certain areas? Etc.
To insist that female circumcision is an expression of popular piety amongst Copts is unwarranted, irrational, and downright ludicrous.