When you break the block an item frame is on while the gamerule doTileDrops is set to false, it still drops.
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Comments 6
This can't be what the OP is talking about. What he probably means is that item frames always drop themselves and their contents as floating item entities when doTileDrops is set to false, even though destroying it normally drops nothing as intended.
The item frame is not a drop of the block, it's an entity.
What else should the frame do ? Stay floating in the air ?