Judgement of the Pure lasts for 60 sec and Judgement has an 8 sec cooldown. Even if you missed a couple times in a row, it would seem like you would have ample opportunity to still get the buff up (and even if the buff falls down, your healing doesn’t totally collapse). Judgement costs 5% of mana, so it’s hard to imagine that’s a huge mana loss if you miss.

I would consider that +hit as optional for PvP, soloing or when you just want to burn things up in a 5-player run. (Source)