Traitorfish
The Tighnahulish Kid
There might be something to it, but I can't see it as a glance. We can roughly break traditional Irish names down along these lines: names associated the Hiberno-Normans were those with a direct French equivalent, like "Sean" for "Jean", while names of purely Gaelic derivation, like "Finbar", would be associated with the old Gaelic families. But this division doesn't seem to carry forward to modern associations, so that both the Hiberno-Norman "Liam" (abbreviated from "Uilliam", from the Norman "Guillaume") and the Gaelic "Keiran" both carry low-status associations, while neither the Hiberno-Norman "Eamon" (from the Norman "Edmund") and the Gaelic "Fergal" don't carry those associations.Well, you have two distinct waves of English invasions of Ireland, one with the Normans in the 1100s and one with the Tudors and Cromwell in the 1500s-1600s.
I might hazard the guess that the names incorporated by the progressively Gaelicised Catholic Norman-English overlords became more acceptable, since England was also Catholic at the time, and that anything that still remained utterly and distinctively Irish when the Tudors started their reformation -which is essentially against the Pope- gets the disrespect.
I'd need a reliable list to test this out.
Probably the missing ingredient in all of this is just the arbitrary winds of fashion; for instance, the popularity of "Liam" in the UK seems to coincides roughly with the lifespan of the band Oasis. That the Gallagher brothers happened to be of Irish origin might just be a coincidence. (And in fact it probably isn't, because the outsize influence of the Irish in British popular music is another Thing in itself- three out of four Beatles, ferchrissake- but let's stick to one rabbit hole at a time.)