Many debates degenerate into flame wars, where contributors are compulsively rude to each other and the point of the argument is lost completely. Almost everyone finds more than one group interesting and some groups receive hundreds of messages a day. A typical session that checks for new messages once a day might take a few minutes to collect the most recent postings. Each newsgroup has its own customs and taboos, and some groups are extremely hostile to newcomers who don't learn about these before contributing. But the network as a whole does have its uses and can sometimes serve as a good source of entertainment.
Many groups are local, or exclusive to particular countries.
Although these groups appear on the international network, the content isn't relevant to anyone who isn't fluent in the local language. In some cases messages are posted in a completely different alphabet to the English one, which makes them impossible to read on any computer that isn't equipped with special language hardware. These list and answer the kinds of questions that newcomers ask, and provide a good introduction to each group. They're often an excellent source of information on the subject matter of a group. Sometimes getting a copy of the FAQ, which usually appears as a regular posting to the group, is all that's needed to answer a question.