I'm not sure what they are getting at by "roll stats straight up."
Rolling for stats rather than using point buy is still the first recommended option in the PHB: "You generate your character’s six
ability scores randomly. Roll four 6-sided dice and record the total of the highest three dice on a piece of scratch paper. Do this five more times, so that you have six numbers. If you want to save time or don’t like the idea of randomly determining ability scores, you can use the following scores instead: 15, 14, 13, 12, 10, 8."
But that still allows you to assign them. Just rolling once for each stat in order is super old school and if that is what they are getting at, that does seem like a Quixotic argument.