Google hypocrisy on property rights: It is fine for it to "fork" others programing, but not for others to do it to Google

No one really denies that Google forked the Sun's Java when it designed the Android operating system.  What concerned Oracle, which had bought Java from Sun, was that Android use of Java was incompatible with Java.  Google's successful legal defense largely rested on Tim Bray who had designed Java and Google had hired Bray to work for them a couple of years ago.  Here is a statement from Bray:

But I think there’ll be lots of forks, and I approve. I suspect that basement hackers and university CompSci departments and other unexpected parties will take the Java source, hack groovy improvements into it, compile it, and want to give it to the world. They’ll discover that getting their creation blessed as “Java” requires running the TCK/trademark gauntlet, which isn’t groovy at all. So they’ll think of a clever name for it and publish anyhow.

Which is terrific. I see no downside, and I see huge upside in that the Java mainstream can watch this kind of stuff and (because of the GPL) adopt it if it’s good, and make things better for everybody.

So Google's argument was that when it was doing the forking, it was fine, even good.  Obviously, both Sun and Oracle didn't see it the same way and were worried that the incompatibilities would hurt programing for their version of Java.

Well, what a difference a few months makes.  Now Google is forcing Acer to drop the release of a new operating system to compete with Android that involves forking of Android.  Google of course is now making the same argument against Acer that Oracle made against Google.

In a blog post today, Rubin called out Alibaba's Aliyun platform as a forked version of Android that's modified to the extent that it's incompatible with other Android devices. As a member of the Open Handset Alliance, Acer is forbidden from using such an operating system, he said.
"Compatibility is at the heart of the Android ecosystem and ensures a consistent experience for developers, manufacturers, and consumers," the company said in an e-mailed statement. "Non-compatible version of Android, like Aliyun, weaken the ecosystem." . . .

The irony of this is not lost on Alibaba:

"Aliyun OS is not part of the Android ecosystem so of course Aliyun OS is not and does not have to be compatible with Android," said John Spelich, vice president of international corporate affairs for Alibaba. "It is ironic that a company that talks freely about openness is espousing a closed ecosystem." . . .

Google said that while it built its own operating system, Alibaba took elements of Android to build Aliyun. . . .

So didn't Google take parts of Java in building its own operating system?  Could someone please tell me what I am missing here?  Thank you.

UPDATE: The two examples are becoming even more closely linked.  Alibaba claims that its new Aliyun operating system is not a "forked" version of Android, just as Google claimed that Android had not "forked" Java.  Google obviously had to eventually concede that it had forked Java, but their defense was that it was great to have a lot of innovation.  Will it become clear that not only is Google making the same argument that it railed against before but that Alibaba hasn't forked anything?  From CNET:

Chinese search giant Alibaba is disputing Google's claim that Alibaba's new Aliyun operating system is a forked and incompatible version of Android and thus can't be used by phone maker Acer.

In a blog post yesterday, Google's Andy Rubin said "the Aliyun OS incorporates the Android runtime and was apparently derived from Android."

CNET asked Alibaba's John Spelich about Rubin's/Google's claims and about whether there are elements of Android in Aliyun, and here's what we got in response: "They have no idea and are just speculating. Aliyun is different." . . .

But Spelich told CNET in an e-mail that Aliyun is "not a fork. Ours is built on open-source Linux." And he added that Aliyun "has our own applications. [It's] designed to run cloud apps designed in our own ecosystem. [It] can run some but not all Android apps."