I think that is absolutely true, PennyMordauntsLadyBrain.
There is nothing innately difficult about Irish names RCohle. Many rhyme with English words. Many are short.
There seems to be an inability to accept that the spelling of Irish names will involve Irish orthography, not English. There is incredulity and complete inability to wrap heads around the spellings. Why would the spelling and pronunciation of an other language entirely be the same as English spelling and pronunciation? Do people think that Irish is just English with a funny accent?
Meanwhile, there are lots and lots of words in English whose spelling makes no sense at all, but they are accepted.
Not having a link to Ireland doesn't mean you can't use an Irish name (in the opinion of many Irish people though, parents should take care to spell and pronounce the name correctly). I am not sure how the issue of using a name outside of one's culture would cause annoyance if the name was apparently difficult to pronounce. There are many names that are not ethnically English whose pronunciation is not obvious but I doubt there is a problem - thinking of names like Penelope here.
I am not as familiar with names from some African traditions, so I can't address difficulties with them. From what I see of names from African traditions, though, they seem to be spelled phonetically.