Plus, there's the issue of diacritical marks. Irish keeps long marks over capitals, but French drops accents. Do you plan to do é => É (required for Irish - POBLACHT NA hÉIREANN is the all-caps version of Poblacht na hÉireann [the Republic of Ireland]) or é => E (common practice for French)? You have to get it right, and you have to know the language to do that. (Poblacht na hÉireann also illustrates the fact that initial caps is also a language-dependent idea; you absolutely can't write Poblacht Na Héireann - that makes my eyes burn just looking at it.)
(And before you say, well, Irish isn't a language spoken by very many people, remember that it's an official language of the European Union. If you're writing software to be used by EU agencies, you're going to have to care.)