Is there anything worth saving from GAZ10?
Good question.
To back it up even further: is there anything worth saving about the Broken Lands of Thar?
I'd answer: Yes.
The Broken Lands first appeared seven years prior to GAZ10, as a one-paragraph write-up in Tom Moldvay's and David "Zeb" Cook's
X1: The Isle of Dread (1981):

After that, there were sparse and weird references to the Broken Lands in a few random modules.
Only in 1988, with GAZ10, were the Broken Lands filled out--and filled out in this problematic way. Furthermore, the weird and cool references from earlier modules were not really synthesized and included in GAZ10. Where were the "outcasts" mentioned in X1? GAZ10 could have gone in a different direction.
But, if you overlook the real-world racial/cultural ugliness, game-wise GAZ10 was innovative in providing advancement levels for goblinoid/monstrous PCs. It was the template for the
Creature Crucible line which came out a year later and which likewise gave advancement levels for all sorts of monstrous PCs (fey, aerial, underwater, and lycanthrope PCs); and, in this regard, GAZ10 was also the predecessor of such products as 2E's
Complete Book of Humanoids, and 3E's
Savage [sic]
Species, where Level Adjustment was introduced, which was kind of a "thing" in 3.5e.
If GAZ10 didn't contain such ugly real-world-based racial slurs, there would be no petition. The issue of general fantasy biological determinism (e.g. orcs are inherently dim-witted and evil) is a separate issue. If that's all that was the matter with GAZ10, then likewise, there would be no petition.