Agreed. It seems that there is just about no way to refer to Catholics who belong to or follow or what ever, the Roman tradition headquartered in the Vatican without offending some one, some how.
The term *catholic* does mean universal and the Catholic church cannot justifiably lay claim to the term as its own.
Since there are also other sects of Catholicism which use the word *Catholic* in their title and have slightly different teachings from the Roman Catholic branch, as in *Ukrainian Catholic*, then by designating *Roman Catholic* you are referring to the specific branch of Catholicism.
Since the word *Roman* begins with the letter *R* and the word *Catholic* begins with the letter *C*, it is completely reasonable to use the abbreviation of *RC* to mean *Roman Catholic* regardless of whatever meaning someone managed to attach to it some hundred years ago or so.
The objections to the use of this term remind me too much of the Asians in Atlanta who are complaining about the metro lines which were color coded. They didn't like *Yellow Line* because apparently the yellow line ran through their Chinatown, and they are now demanding that it be relabeled.
Well, they better not change the line to red or the Russians will be upset.
And not green since the Irish might object.
Not white because that would obviously offend blacks.
And not black because whites might not like it.
Green is out because it's obviously too politically-correct.
How about blue? No one has yet co-opted the color blue.
Have they?