> As far as I understand it the vast majority of rockets have uncontrolled

I don't think that's true anymore. There's a Danish radio program[1] that talked about this and apparently China is the only country/operator that still have uncontrolled reentry rocket stages. Everyone else have committed to controlled reentry.

Looking that the possible places where the rocket can hit populated areas. It looks like they went out of their way to ensure maximum coverage of Africa. Reentry a little earlier and they would have been almost ensured that it would hit the Atlantic Ocean.

[1]: https://www.radio4.dk/program/den-nye-rumalder/?gid=43389&ti...