I'm not a Delta flyer, so I may be misunderstanding - but I don't think that's an apples-to-apples comparison. The OP and others are referring to when a mode of transportation offers first and business simultaneously - and where business is by definition the higher class of service than first class.

On most legacy USA-based airlines, it's a marketing term to call the front of domestic fights "first class" on 2-class flights. But on flights where there are first, business, and economy classes, "first" always is a higher class of service than "business."