The problem with what you say is that you use English as the standard of how to use the Latin alphabet, and label Irish as 'different'.
How about looking at from the pov of Irish (or German, Italian, Hungarian, Finnish, Norwegian, etc) being the standard? English would come out as a monumentally mongrelised language with an insane orthographic 'system'.
'no other language, to my knowledge, uses the Latin alphabet in such a very different way.'
That is a completely subjective notion of another language based on an insular, anglocentric world view. Look at the ISO 8859 Latin 1 to Latin 4 character sets -- they exist because the 'Latin alphabet' has major limitations where European languages are concerned.
Those letters of the Latin alphabet that are used in Irish do the job in a highly systematised and regular way. J,K,Q,V,W,X,Y and Z are not used as there are no corresponding sounds. There is one diacritical mark, the fada. If you think the letter combinations are weird looking you have misheard the sounds and you are ignorant of the grammar. The combinations that exist are all there for a solid reason related to grammar and phonetics (the representation of the actual sound of the language). Newe would not be an accurate Latin alphabet rendition of Niamh because Niamh is pronounced Nee-?v. If you have heard Neev you have heard a mispronunciation. There is a schwa in there [?].
By way of contrast, English spelling is not by any stretch of the imagination related to the sounds of English. On the one hand, it lacks a huge number of modifying marks above and bisecting letters that are found in Czeck or Norwegian for example, but it makes up for that in spellings that still cling unnecessarily to the language of origin of many of the words although it has divested itself of most of the original sounds hundreds of years ago. English is one of the most difficult languages to learn if it's not your first language, thanks to the unsystematised spelling.
Runes were predominantly the earliest forms of Latin and Italic languages and were also used in very early Germanic languages, including the language of the Anglo Saxons. Maybe we can therefore say patronisingly that the scribes who laboured to alphabetise most Germanic languages did their best, and shake our heads?
Ogham isn't strictly speaking a runic language, and as your link explains, its origins and uses are still being debated. You can't really claim it was used by rebels, as there was nobody to rebel against at the time Ogham was in use..
'Your complaint would be reasonable if speaking about English people in Ireland & not bothering to try.'
Not really. Britain is now a multi-ethnic society and people who consider themselves British rejoice in a huge variety of names from a huge variety of ethnic and religious backgrounds. Furthermore, Britain has a long history going back several hundred years of incorporating the entire island of Ireland into its body politic. Until 1922 your ancestors and mine lived in The United Kingdom of Great Britain and Ireland. Mine learned English in acknowledgement of the fact of close proximity.