Gotta remember some things.

Greg's conversation with Steven.

"No such thing as a good war, kiddo. Gems were destroyed; people, too. In the end, your mother could only save a handful of her closest friends."

Then there's the state after the world. Busted up Gem architecture everywhere, "Corrupted Gems" and how the Crystal Gems are mainly on clean up duty. Peridot's logs seems to be inaccurate based on what she knows of the war, and how she believed Earth was inhabitable for Gems.

And finally JASPER saying she respected Rose's battle tactics.

I think Rose unleashed some kind of cataclysm that forced Homeworld to abandon the planet.

Not to mention Peridot said she read over 200 YEARS of reports about the cluster, so this stuff has been going for a lot of time.