You put a period in that sentence where there wasn't one. I said "darker roasts are easy to achieve consistency with", and as you said, to help better facilitate the commodity approach to coffee.

Dark roasts are not more shelf stable than lighter roasts though. The oils in dark roasts become rancid substantially more quickly because a darker roast has expanded more, and therefore has more surface area to come in contact with air. Starbucks and other big companies say their coffee is shelf stable for about a year, but the reality is coffee peaks 24-72 hours after roasting. Burnt notes grossly outweigh staleness though. That with the benefits of consistency is great for bigger brands exactly for the other reasons you mention.

To add a bit more perspective, green unroasted coffee beans are considered fresh or in season for about 9 months. The more you get away from this in a roast profile the shorter the shelf life.