Well, the Argentinian, Spanish, and Mexican scientists can all use
Spanish (and probably still not lose the Brazilian audience), but I
recognize your point. The real question is: Is reaching an
international audience the primary priority of all papers? Yes,
English will reach the widest audience, worldwide. But if you're a
speaker of another language who's writing on a matter that may be of
more interest in your sector of the world than it would be to
foreigners, it may make sense to use another language. Why gain
readers on the other side of the globe at the risk of losing readers
close to home?