That page says: "The use of XCF as a data interchange format is not recommended by the GIMP developers, since the format reflects the GIMP's internal data structures, and there may be minor format changes in future versions."

It still seems like a better basis to fork for a format than something new and untested.

Something you don't control — and which the people who do control it say "don't use this because we'll probably change it often" — is somehow better than something you do control?

> fork