[oskarkk]

I assume the GP is talking about the fact that almost every rocket, except SpaceX' Falcon 9 and the Space Shuttle, is designed to be dumped in the ocean. Specifically the first stage of a rocket usually falls down into the ocean at a relatively high speed (probably in pieces), but it's speed is usually not high enough to burn up. The second stage of a rocket goes all the way to orbit with the payload, achieving speeds like 7 km per second, and then reenters the atmosphere and burns, but some pieces can still come down intact, so it's preferably also over the ocean. The second stage may also stay in space indefinitely, depending on the target orbit of the payload. Anyway, dumping space stuff in the oceans is the default since forever.

SpaceX' Falcon 9 is an exception, because its first stage is designed to land on the barge in the ocean or fly back to the coast and land on the landing pad, allowing it to be reused. Falcon 9's second stage still burns up/breaks down in the atmosphere after launch, in a controlled way (over the ocean). The goal of Starship is to have the first ever wholly reusable rocket, of which no part will be dumped in the oceans.

In the case of the last flight of Starship, it obviously wasn't meant to explode inflight, so the place where the debris has fallen was much closer to any land than the usual "intentional" rocket debris. If the flight was successful, Starship's second stage would simulate landing in the Indian Ocean and then sink (and probably also explode while sinking and the debris could show up on the coast of Australia). They aren't allowed to land this thing on land yet, and with this failure they certainly won't be allowed to do that soon.