I don't know much about Christianity or Islam, so I'm not claiming any particular degree to which any of the following is unique to Judaism, but Judaism includes the following features that motivate people to share lots of questions and answers about it:
A vast, rich literature, developed over the course of millennia, with more being added every day.
The literature includes modes such as lore, law, poetry, ethics, and mysticism.
Large amounts of the literature are considered to be Divine in origin - either written by God, written by prophets in contact with God, or originated as an oral tradition by God.
Communities of adherents who pattern much to all of their lives on the laws and ethical teachings found in the tradition and literature. (And therefore comprise a complex living embodiment of the tradition.)
A core mandate for all members of the community to spend time learning and becoming expert in the literature, throughout all stages of life.
A tradition of weekly public reading of sections of the core text (five books of Moses), completing the text over the course of the year, driving communities and individuals to study and discuss the weekly section and commentaries and related texts.
A great deal of the legal literature consists of questions and answers. The Talmud is full of accounts of rabbis posing questions to each other to request information or rulings or to challenge each others' positions. Much of the development of legal concepts through the centuries came through precedents set in rabbinic respsonsa, in which formal questions posed to a rabbi and the responding rulings are published together.
One key annual ceremony - one of the most popular across the Jewish world - is conducted by families joining together at home, and features, in various ways, participants posing questions to each other. (This Stack Exchange community is named after a song containing one set of such questions.)