Google is under no obligation to host any particular library, I think in this case due to the ExtJS split licensing they made the correct decision. Also consid

Google is under no obligation to host any particular library, I think in this case due to the ExtJS split licensing they made the correct decision. Also consider that by offering this code on their CDN it would be possible to argue that Google itself was deriving a commercial benefit from the code in question and therefore should purchase a license.