Some people cherish their heritage, which includes language. That's why we see efforts to preserve languages in Europe, France being the exception - Occitan is looking pretty endangered right now.
While there'll always be a few dominant international languages, with one ascendant, unless there's a concerted effort to stamp them out then there's every chance local languages will likely continue.
One the other hand, there is the example of modern Hebrew, which is a "Lazarus language" in many ways. It was a liturgical language and now it is certainly a vernacular language. It is now an everyday spoken language in wide print and usage.
There is certainly a movement towards seeing many languages go out of use, but with modern learning and preservation methods, many languages that looked as if their would go extinct, are now surviving and prospering. The language of the Isle of Manx. Modern Irish. Many Asian languages that Chinese conquerors had once tried to stamp out. Coming back... LOL
Shalom,
Maksim-Smelchak.