You'd think the UK would be alright with it given Irish names are and were reasonably common (at least in parts of the UK), which commonly have fadas in them (i.e. Béibhinn, Seán, Ciarán, etc)
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.
^ comes from typewriters, where it was used to type letters like â by backing the caret and typing over the last letter. Similarly ' could be used for acute accent - hence why it didn't get a separate letter - and ` for grave accent.
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.
