So I recently got some new shoulders off of the gracious and mighty Ordos, and didn't upgrade them. I went on Mr. Robot and he told me what to do, so I was sitting at like 15.40% hit.
Well I decided to 4/4 those shoulders and when I redid my optimization on the site, it said..I don't need to make any changes? I'm at 17% hit right now, with like 4 hit gems and it says I'm 100% optimal. I'm confused?
There is an issue currently with the official WoW armory not updating. Mr Robot pulls its data from what the armory says so atm it is not pulling the changes you have made and it won't until they correct the issue. Blizz knows about the armory issue and they said they are working on it, in the meantime my suggestion is manually figure things out with the gear/gem/reforges to get to 15%.
Pretty much every piece you have has hit. Maybe you just have too much of it to reforge down to 15% efficiently. If it isn't a bugg, you may be the most optimized you can be until you find better pieces.
Also, you can crank out 7% more haste while losing 4% crit by switching to the "multi dotting" destro build on AMR, and editing weights to change mastery value from 4.6 to 5.0. Thats the best stat weight you can use as destro.
You have a LOT of hit on your gear, so with the mixed gems AMR wants to use, you go over the hitcap. You could replace some of the mastery/hit gems with mastery/stamina, because the reason AMR wants you to use hit/mastery is because the socket bonus is worth getting even with half a gem being wasted, so you might as well go for stamina instead of hit, as at least that benefits you a little bit whereas hit gets you nothing at all.
But really, there isn't a lot you can do other than try to get some gear without hit to replace a few of your big hit items.