People of the Book

Qadiani Ahmadis don’t pray behind Muslim imams, because Muslims reject their prophet Mirza. They consider us “people of the book” insofar as they would allow Muslim women to marry Qadiani men, but wouldn’t allow Qadiani women to marry Muslim men. (Lahori Ahmadis don’t have the same rules.)

Qadiani leadership allows its members to pray in Muslim mosques, so long as they don’t pray behind our imams.

The question arises, given that we are just considered people of the book by them, why don’t they pray in churches or synagogues too?