If RoA was weaker, quite a lot of mages would be struggling. It's so all-encompassing, you can't really go wrong with RoA. It gives mages much-needed survivability vs all the full-damage teams in the game right now.
Abyssal tends to create a dichotomy as it exists currently. AP assassins will build it vs mages, so that usually necessitates that those mages (if abyssal is viable on them) also build the item to counter the stat-check, otherwise RoA is your best option for survivability.
On another note, Lich Bane is another item which received no nerfs/price reductions and actually gained more movespeed and CDR. Athene's and Morellonomicon both became 100g cheaper. Void Staff will always be strong, unless it gets reworked like Last Whisper.
The only AP item I see complaints about is 
and usually relative to 
, and I see those complaints as justified- Armguard gives no active component like Hexdrinker does with the shield. Not to mention AD champs also have access to Mercurial Scimitar, while there is only one dedicated AP/Armour item.
Besides, not every mage is interested in RoA/Abyssal 



, to name a few.