Ladders can be problematic for a motorhome manufacturer. They aren't the toughest things around and have a limited capacity, which is generally beyond most owner's "unloaded" weight.
Liability becomes a big factor. The rear cap needs to be divided between taillight areas and a wide enough engine access hatch, which leaves little room for a ladder. With the 2016 Entegras the new cap and embedded side awnings leave a rear light bar across the top. This would require a ladder to stretch up and over that bar or else the guy has to be a gymnast to move from the ladder to the roof. I can see why ladders are beginning to go away in the industry. The Little Giant type ladders are handy because they can be used as an extension or stepladder, which is handy for cleaning windshields or similar uses.