Ice climbing is already a dangerous sport. Why compound the problem with hard to place screws.
There you are on a vertical column hanging off a single tool, forearms starting to build lactic acid and your screw just will not start.
How about that thin run-out that only takes tied off 10's. Wish you had a Super Stubby?
All ice screws are sharpened using a CNC milling machine. This produces precision teeth that are sharper than new. Sharpening only removes about 1mm. So sharpening a screw 10 times changes a 17cm into a 16cm.
To keep the price competative we collect all ice screws by a deadline and machine them as one large batch.