I can see it as miserly, but I wonder if it's some kind of attempt to select for the kind of customers they want, i.e. customers who are themselves not too mise

I can see it as miserly, but I wonder if it's some kind of attempt to select for the kind of customers they want, i.e. customers who are themselves not too miserly. The 20gb tier is absurdly cheap, $0.99/mo. So much so that they wouldn't be giving up much real revenue if they just bumped the free tier to 20 gigs, but then on the other hand it doesn't cost a user much to go up to that tier, either. Maybe the threshold of "people who will/won't pay $1/mo for iCloud" therefore serves a useful function for Apple?