I really don't think this is just for people who don't have personal computers. I do think this is for people who don't want to carry additional separate devices with them in order to access the bigger-screen experiences. There are a couple gimmicks based on the fold as well.

I for one would love to have my phone turn into a tablet while I'm charging my car. Saves me from having to bring the iPad separately, which can't fit in my pocket. Would eliminate a step from that routine.

Also would love to always have that capability on me in the case where I couldn't have foreseen a need for the bigger screen. Being randomly out with friends and able to spontaneously just show them something in a way they can actually see would be nice.