Genuinely curious - why is China doing uncontrolled reentry any different? As far as I understand it the vast majority of rockets have uncontrolled re-entry, save for spaceplanes, falcon 9, and more recently electron.
"Controlled reentry" isn't necessarily synonymous with "booster recovery". Most rockets have a way to deorbit the upper stage once its job is done, either by firing the main engine retrograde, or using a small dedicated deorbit motor. By firing the motor about half an orbit before the projected reentry point, you can control exactly when and where the stage will reenter the atmosphere, hence controlled reentry.
Second, the Long March 5B is somewhat unique among rockets in that its large main stage stays with the payload all the way until orbital insertion. Most other rockets drop a large majority of their bulk long before it has enough energy to stay in orbit for any appreciable amount of time. Probably the closest comparison in this category is the space shuttle's big orange external tank, as it provides fuel for the main engines until just a hair below orbital velocity, but it's subsequently jettisoned and the orbit is completed using the shuttle's onboard thrusters.
So you have a combination of (no deorbit capability) and (big tank floating in orbit) that results in (big tank crashing down at an arbitrary location whenever it feels like coming down to earth).
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...
>In 2020, over 60% of launches to low Earth orbit resulted in a rocket body being abandoned in orbit
>In the USA, the Orbital Debris Mitigation Standard Practices (ODMSPs) apply to all launches and require that the risk of a casualty from a reentering rocket body is below a 1-in-10,000 threshold4. However, the US Air Force waived the ODMSP requirements for 37 of the 66 launches conducted for it between 2011 and 2018, on the basis that it would be too expensive to replace non-compliant rockets with compliant ones
I do think China's space program is more irresponsible than USA/EU launches based on some of the debris fall, but blaming uncontrolled re-entry seems like the wrong thing here