Quote from: Blizzard (Source)

The non-set items are there to fill out the arena sets, they’re essentially placed there specifically so that arena players have a reason to participate in other aspects of the game. We want to see their faces around, we don’t want them just standing on top of the battlemasters all day.

So, with them being arena items intended to fill out the current top-end arena set, and our increase to rating requirements all around, it’s actually very logical.