A) Fantastic producers -- the production from these guys is phenomenal, and IMHO this is what really "makes the song".
B) Great at writing to a formula. The tunes are "catchy" but I cannot think of anything that would be considered really innovative musically.
There's no sin in that necessarily... it certainly takes talent to "know what works" and "know what doesn't"... and for the type of pop music they do (largely teen pop and other pop formulas), formula is fine.
I will say that pop producers like these guys tend to be really solid in the groove / rhythm department, in particular.
C) Great at artistic collaboration... big pop outfits now write in large groups. Knowing the way many musicians are, that's an accomplishment in itself. :) This probably contributes to the "solid song that isn't innovative" aspect... all the left-fieldisms of an artist are probably smoothed out. But again, this pop.
Overall the music product is a professional creation, designed for a market that always was and always will be half song-and-dance youth fashion show as one of the posters alluded to. :) Not a music style I care for personally.
But a popular one, and it takes something to do it as well as these guys do.
Innovation is hard to objectively measure. I judge most music by whether I enjoy it, not how "innovative" it is. Innovation is nice, but "like" is much better. Most styles are cyclical and borrow from the past. Disco-esque music has come back twice. Anything "new" is probably just borrowing bits and pieces from different eras.
If it were easy, anybody with money would make a hit. If they make a catchy song, I give them kudos regardless of how they made their sausage. To quote a pop song: "Shuddup and dance!"
But anyone with money and the right relationship with the distribution gatekeepers pretty much does.
True, it could take multiple factors, such as the best writers plus the best arrangers/producers plus the best musicians plus the best distribution channels. But all those prerequisites still means it's not trivial to do right. It's like the NBA: the best players and best coaches and best owners tend to find each other and gather.
What really isn't that clear with these songs, and I believe that's why so many people dislike them (altough they agree they sound catchy) is because the performer of the song isn't necesarilly the creative force behind the song; as it was proven with the video of how the song "Middle" came to be. The girl that sings the song actually played little part in the creative process, and is part of the song because of her voice and probably looks.
A good comparison could be with Hollywood movies. No one can argue that they are extremely produced and market focused; so, when you hear a song by Katy Perry or by <replace_with_trendy_name> is the performer a good actor or a good director, or both?
It is easy to argue with success if you could prove it was due to cronyism. :)
>Cronyism alone can't create catchiness.
I don't see how cronyism could create catchiness at all but cronyism could account for the perception that only two people can do it when the actual number could be a much highe.