I'm sure the majority of Drow society would be mighty pleased indeed knowing heroic adventurers are prancing around with their equipment, selling extras off to svirfnebli, duerger and the likes.
The esoteric nature of Drow weaponry in their society means that they protect the secrets of their creation at all costs.
Also, I think Illumina made a good point in saying that the well seasoned and prepared adventurer has no real need for drow equipment on the surface anyway. There is enough magical armour and weaponry in SoA as it is to compensate. It adds character to your struggle with bad AC just to find them too.
