Acceptable to spirit bind in Dungeons?

[Noahlimits]

I recently went into a WP run where a DPS (wearing relic +1 and full DL) switched to all white items (including weapon) to spirit bind. Is this acceptable behavior in a dungeon?

To me, he's making the dungeon take longer then it has to all so he can get materia. Everyone else in the party was decently geared (one garuda weapon +dl, healer and tank had relic or relic+1). I could kinda understand if it was just a single accessory or armor piece, but the full gear list?

Am I overreacting or is this acceptable?