I disagree. We use modern computer technologies. Those few special characters belong to our languages. I cannot imagine any reason why modern software plattforms could and should not handle them! They’re just letters! Softwares can build CG-Citys and replace actors, but they fail when they have to deal with an “ä”.
Besides, of course, everyone should know this, and try to avoid them, but that should be no excuse for the software developers. And fact is, that I regulary get sessions with those characters for mixing jobs.