in what ways was children of men exclusive- what did it imply or hint at without ever addressing explicitly. what do you think of this approach to film-making

This film is amazing. Director Alfonso Cuarón creates a dystopia like no other. As far as your question, they never give a reason why children are not being born. THere is speculation but suffice to say it is probably something humans have done. Interestingly is is made clear that at least some mammals are able to have offspring (i.e. the kitten on Theo's leg). Let me know if you have any other questions, this is one of my favourite filmes ever!!