Last week Acer was scheduled to hold a press event to launch a new smartphone running the Aliyun OS from Alibaba. Aliyun is built on the Android framework, but is a totally different fork of Android that according to Google renders it incompatible with the Android ecosystem. The launch event was cancelled at the last moment due to pressure on Acer from Google to stop the madness.
Acer immediately jumped in with a public complaint that Google was not being very open with Android. Alibaba also lamented that if Android was really open then Google would not be pressuring Acer to stop using it.
According to Andy Rubin of Google the company stepped in not to stop this fork of Android but to stop Acer from violating the agreement it entered when it joined the Open Handset Alliance (OHA). That is an alliance of OEMs who joined up early in the life of Android to promote the use of the platform for the good of all. Rubin states that the members of the OHA agreed to not use forks of Android incompatible with the ecosystem, and that Aliyun definitely fits that description.
"However, the fact is, Aliyun uses the Android runtime, framework and tools. And your app store contains Android apps (including pirated Google apps). So there's really no disputing that Aliyun is based on the Android platform and takes advantage of all the hard work that's gone into that platform by the OHA. " — Andy Rubin
Rubin also stated emphatically that Aliyun is based on Android, even including pirated Google apps. That's a telling statement and likely the reason behind Google's stepping in to stop Acer from using it, as the OHA agreement allows.
So Acer invoked the ire of Google not by using a fork of Android, but for using an incompatible fork in violation of the OHA terms. That's not the same thing as forcing Acer to stop using this particular fork of the platform just because Google doesn't like it.
The biggest fork of Android is the system Amazon is using on the Kindle Fires, and Google is not trying to pressure Amazon to stop using it. The reason is simple -- Amazon is not a member of the OHA and has not agreed to not do so. Acer would be in the same boat as Amazon if not for that pesky OHA membership which forbids the practice.
So this has nothing to do with the openness of Android (or lack of it). It has everything to do with the agreement that OHA members enter into that is designed to protect all the members from the very thing Acer has done with Aliyun. Or not done, since Google has successfully pointed out to Acer that it is in violation of the OHA.
This type of agreement is standard for alliances of this type. Members who join, while competitors, often agree to not compete in certain ways. This forms the basis of the alliance agreement that Acer has now violated according to Google.
This type of agreement is similar to those of many homeowners' associations or condo groups. You buy a condo and you sign an agreement defining what you can and can't do that might adversely affect the rest of the condo owners.
For example, a condo agreement may prohibit the use of red front doors for whatever reason. If you as a new condo owner paint your door red you are in violation of the agreement you signed upon joining the group. It is no surprise the condo group will immediately demand, legally if necessary, that you repaint your door an approved color.
That doesn't mean the condo group is trying to control what you do with your own condo. It is enforcing the agreement each owner enters to preserve the value of the property as a whole. This is exactly what Google is doing with Acer and the OHA agreement. It's not about Android, it's about protecting the ecosystem as Rubin has stated.