Are you taking into account stats from all of the other ilvl 100 gear? Accuracy probably drifted somewhere else in the shuffle.
Edit: New gear sets means you need to let old things go, your stats aren't going to be optimal for awhile again and if you don't realize that, you're going to be left behind.
I'm taking over all stats into account, using the tools available on XIVdb.
Bottom line is this. I can get away with a little less Perry since newer gear has higher base defense, but I can't get away with less accuracy. The cap in turn six means I'll start missing bad if I don't keep my accuracy stats up.
None of the ilvl 100 weapons that are immediately available have accuracy, and accessories have no real base defense stats, the ilvl on them is largely ornamental.
So a higher ilvl accessory isn't always better. Where as higher level armor is almost always at least slightly better.