I don't think he was intending to make any difference in her success or spreading misinformation. Putting aside his opinion and the real driving force behind his video which is his conviction that the Beatles songwriting is just superior to hers (I probably tend to agree with him but I am really not a huge fan of either), what he says about pop music sausage creation shouldn't be outright dismissed because of how one feels about Taylor Swift.
I think he is right in his assessment of how pop music tends to be produced these days and he is right that other people in the room are doing way more than consumers realize. That doesn't diminish her tremendous success but I could see why someone who thought all the output is all her and 'she's the songwriter' might get defensive. What Rick describes is not a unique or new arrangement in popular music...extremely talented producers do heavy lifting all of the time. I see no reason why what he said about this sample of her music - that her output is a sum of musical contributions that go beyond her alone - must be false given the prevalence of these artist-producer relationships.
Some things in the music industry can be funny in. I never appreciated there was this whole army of talented women behind so many timeless songs until I saw 20 Feet From Stardom. When I listen to Elvis only later did I realize he didn't write his own songs; but it doesn't diminish him. Outside of music, I understand that when I read an opinion attributed to Justice XXX that there was more than likely a first draft written by very talented law clerks whose names few people know. When I read an equity research report I know that the analyst whose name appears on the report gets the credit, but he has a bunch of co-workers creating the models and writing the draft. I understand why accepting some of what Rick says could be upsetting but it doesn't have to be.
It's funny, because I watched a little bit of that Beatles thing that Peter Jackson did a couple years back, and there were like 15 people in the room when The Beatles were writing those songs in that movie.
I kid, and I know it wasn't the same thing Beato is talking about, but the idea of producers and executives having input into the creative process for artists isn't anything new. I think it's all probably just done a bit more to the nth degree these days (not necessarily for Taylor, just in general).