OP's not asking for AoE SS during battle. OP just wants a massive Quality of Life improvement: AoE Stoneskin outside of battle, to save time during the beginning of the raid.

Yes, it takes only 24 seconds. Now multiply that number by the number of raids that asks for raid-wide SS which itself is first multiplied by the number of wipes that raid suffers.

Literally hours are spent to SS the whole raid. Allow SS to be AoE outside combat, that's something everybody can agree