2. In retail environments it allows people to see the difference between a retina display and a regular display. They will 99% of the time buy a retina equipped device afterward.
No offense but I'm trying to figure out your logic on this one and I'm getting twisted up...
Apple kept around a lone non-retina ipad model when all the others moved to retina so that people would buy a retina device? Wouldn't just getting rid of the non-retina model accomplish the same result?