I mean, English itself has diacritics in perfectly ordinary words that many Americans use every day (café, résumé, and yet somebody decided to put "useless" characters like @, ^ or # in ASCII instead.
By the way, the accents can often be used to force the right pronunciation of a foreign name on native speakers (at least in US, where Spanish names are so widespread). So e.g. use "á" if you want it to be pronounced [a] etc.