I always prefer on-card auto because if card companies can charge us the amount they are charging for a box of cards, they should make products up to the standards that we expect. But it seems to me, it's all about cutting costs for them and their objective is to flood the market with low quality game-used cards and autographs. They forgot that quality is what matters not quantity.
The main reason I am against stick-ons is because most of the time the players don't sign within the sticker. These players obviously have attitude problems and don't give a rat's ass about what they do. But if card companies can make them sign less, they would put more effort into signing, producing full signatures rather than scribbling initials.