As one of the people doing the theorycrafting, I rather disagree with this statement. Shoulders are quite good when the timings work for them. And with the current speed kill timings and gear progression (so you have higher crit and haste for more fury spent per second than before) the shoulders have improved a lot from when we first hit the patch.
Using a 152-168 kill timing, which is in the range of what most of the Trilliax kill times are:
https://imgur.com/a/afoYs
However, when you change the kill time to be 238-263:
https://imgur.com/a/8qTaR - you'll notice that if you get very lucky you can get an extra meta in with the shoulders still, which is why their top end is the highest, but the average case they don't.
You'll notice on my listing for pure ST that shoulders are very high up:
https://imgur.com/a/8gNSv
I've never said that shoulders aren't good. Just that you have to be aware of fight timings and that if you're bad at CD timing then you'll not use them well.