One benefit of keeping languages around is that they help us understand what the brain is capable of. I'm with you on having a universal communication language,

One benefit of keeping languages around is that they help us understand what the brain is capable of. I'm with you on having a universal communication language, but keeping other languages alive does have some benefits. One example is literature - literature often does not translate well at all. Another is psychology and brain functionality, as I say above. For example, there are languages out there that don't have 'left' and 'right' as concepts. Instead people use 'east' and 'west' or 'north' and 'south'. Speakers of these languages tend to have a very good grasp of their geospatial bearing as a result. Without these unusual languages, we would be very unlikely to think of experimenting with such a concept, much less be able to test it. I did hear of one language about to go extinct (in central america, I think). There are apparently only two speakers of it, both elderly, that live a couple of streets apart... and they don't speak to each other because of some feud :)