I would argue that it's not groundless historically, all the western Churches who weren't under the Pope before 1054 like England and Ireland(1066 for the UK) certainly weren't Byzantine in everything they did. I don't particularly like Western Rite, but I don't think it's artificial either.
First of all, Catholic Western Europe, including England and Ireland, was
under the Pope as its patriarch, even though it wasn't all Roman Rite - there was a Latin rite used by the Irish that's long extinct and another Latin rite, the Gallican Rite, used by the French (or perhaps at that point in history one should say the Franks).
Keble already has done a good job on this board of arguing that the notion of the English Church as this Orthodox paradise destroyed by those Awful Romans in 1066 is a fantasy, or as I would say, rank BS.
Western Rite Orthodoxy is artificial and unhistorical for at least two reasons.
1. Reconstructing extinct rites doesn't mean there will be a real following for those rites and there probably won't be.
2. Nobody really does this anyway, though some Orthodox pretend they do. They mimic traditional Roman Catholic liturgical practices and copy Roman Catholic and usually Anglican texts, sometimes byzantinizing them by adding things like the epiklesis
to 'make them Orthodox', an unhistorical bastardization as wrong as Eastern Catholics' self-latinizations (tearing down icon screens and putting up statues to 'make it Catholic'). As Keble has pointed out well, this dishonest, willy-nilly borrowing from all over history is also characteristic of the undisciplined ways of vagantes
Appropriating things not from one's own church's history and calling them 'Orthodox' is as stupid and arrogant - and perhaps just as born from some kind of inferiority complex? - as the dad in 'My Big Fat Greek Wedding' claiming every word is English comes from Greek or Mr Chekov on 'Star Trek' claiming Russians invented and discovered everything.
Yes, the Chalcedonian Church was one until well into the medieval period, but Orthodox
even back then meant the Byzantine Rite church of the Greek eastern Roman Empire and Catholic
meant the Pope's patriarchate. Both sides did and do use both words but those are the monikers that stuck.