What is the reason for permitting the marriage of a fornicatress to a polytheist? Is it due to the enormity of her act or because she has exited the category of believers, even though the general rule is for a Muslim woman to marry a Muslim man?

"It is not permissible in Islamic law for a Muslim woman to marry a polytheist, and there is no reason that would permit it. The verse, 'The fornicator does not marry except a [female] fornicator or polytheist, and as for the fornicatress, no one marries her except a fornicator or polytheist, and that has been made unlawful for the believers' does not mean that it is permissible for a polytheist to marry a Muslim fornicatress. Rather, it prohibits marriage for the fornicator and fornicatress until they repent."