Does anyone know why it is that the cuts in 1968-69 OPC are so bad? On eBay, they always suggest that it was the first cards OPC had made since the 1930s, but that certainly isn't true. They'd been making the Topps cards for years had had been doing baseball and various non-sports as well. It was just the first hockey under their own banner.

Did they change the card stock? Machinery? Something in their process that messed it all up?

Neither 1968 nor 1969 OPC baseball show this degree of miscutting, from what I've seen.

they were just trying to sell gum to young boys

O-Pee-Chee was producing and distributing cards for Topps since 1954 in canada and in 1961 they manufactored the cards under the Topps license as there O-Pee-Chee brand name started to appear on 1961 wax packs and display boxes.
by 1968 OPC surely had some experience in cutting these sheets.
i am guessing that because the cards were a horizontal set up with tight borders that centering was a bad problem in that year. the 1963-64 cards are also tough to get centered but they had a lot of vending boxes around that year making them a lot easier to find in nice centered shape were as 1968-69 OPC had no venders boxes.