Isn't it inconsistent to criticize the legitimacy of Philosophy of Religion?

One major criticism of my book Unapologetic is seriously misguided to the point where my critics are just ignorant. I dealt with it in my book, especially at length on pages 181-184. But I can dispel with it quickly here. The criticism is that it's hypocritical or duplicitous or inconsistent or contradictory and perhaps even self-referentially incoherent to call for the end of philosophy of religion while using the philosophy of religion to do so.

If this criticism is sound then no one can ever call for the end of philosophy of religion. No one. Ever. This criticism forever insulates philosophy of religion as a discipline from ever being criticized. But why must that be the case, unless philosophy of religion is seen as beyond all criticism or justification? Upon what basis does a discipline need no justification? Critics must therefore state why the discipline they love so much needs no justification. But if it needs justification then it's possible that under rational scrutiny it may fail to be a legitimate discipline in the secular university.

Let's assume someone thinks there's no merit to religion. How would he or she go about arguing for the end of philosophy of religion, other than I do in my book? Answer that question, or admit my critics are wrong to disallow what I do in my book. The critics simply end up making up a rule that says, "You can't do that Loftus, because of a rule we made up that you cannot use philosophy of religion to end philosophy of religion." But if I were to accept that rule then my critics should also tell me how to criticize the philosophy of religion, otherwise they're saying philosophy of religion cannot be criticized.

Do my critics believe there's merit to religion? Then that's the real divide, not with what I argue, or how. What other discipline can I use for my purposes, given what I think is the case? One discipline I suggest is science (or the sciences). Other disciplines include Anthropology of Religion, Comparative Religion and Psychology of Religion. What say ye critics, and don't be silent now.