ARAM needs one important change before it can be taken seriously
Before you can even consider adding a ranked ARAM queue, one FUNDAMENTAL issue with current ARAM must be fixed. One of the core rules of the original game mode, that made it fun and not just "Summoner's Rift with one lane lul", was that going back was prohibited. Current ARAM has strayed away from this fundamental rule. If you ever have an even game, you will see stalling, constant backing off and waiting, waiting, waiting. This is not how ARAM is meant to be played.
One of possible solutions is to add an impassable wall ~1500 units away from the furthest point the last minion wave has reached to encourage people to fight.