I always thought the different scripts used for Slavic languages were the result of religious differences. Ie. the Catholic Poles use the Latin alphabet and the Orthodox Russians use Cyrillic. I'm assuming cultural and geographic concerns are involved as well - aren't Czechs and Slovaks both Protestant, at least in theory?
Another example would be the name of Nobel Peace Prize Awardee Lech Wałęsa. Someone must've told American news anchors that the ogonek indicated "an 'n' sound" but forgot to say anything about the slash-l, because the pronunciations I heard growing up were "vaLENsuh" and "waLENsuh", when the real deal is closest to "vaWENGsah".
When I was a kid I asked my mother how his name was pronounced (having seen it in print) and she said /lɛtʃ wɑˈlɛnsə/ which goes to show how intuitive Polish orthography is. Close but no kielbasa.
Another political figure who was a Slav, Slobodan Milošević wasn't so lucky. I have heard every possible permutation of his name ranging from /miloʊˈsɛvɪtʃ/ to /mɨlɑsəvɪk/ but never anything approaching the original /miloʃevitɕ/. Granted, that's hardly a guy who deserved a Nobel Peace Prize so I don't mind so much that his name got butchered.