Hi Martin, well, I read reviews ( including comments here at APUG ) that were generally positive, and then I stocked up in large quantities. I use them because I have several packages of 100 sleeves, and didn't know anything better when I purchased them. The dust attraction is annoying but can be minimized by keeping unused sleeves in the original package until use, and then keeping the sleeves in a box or sealing ring binder. On the positive side, the plastic is clear and you can make nice contact proof sheets with them. But the answer to your question for me is "because I didn't know."