Exactly. I did layout for awhile. Some boards you knew weren't going to come back. Customer was just paying for us to turn a schematic and BOM into a board with the least amount of cost possible. Quoted low. You could let the autorouter have at it. But other boards (especially finicky high clock speed chip tester boards) would definitely be coming back. Sure you could let the autorouter do its thing, but when that board came back for a rev, I'd have to fuck with all of that laziness to make space for new components or reduce the layer count.