Why won't excellent developers participate in open source after entering Google?

From http://timyang.net/google/open-source/

 

Many excellent developers were very active open-source contributors before entering Google, but they often disappeared after entering Google, including the memcached author Brad, who laughed at this phenomenon, cannot escape this rule after entering Google. Brad talked about the reasons in a recent article about contributing to open source projects.

• Many excellent developers like programming very much. They like to study interesting and challenging questions and do not especially care whether these projects are open-source.
• Everyone is too busy. Google seems to have exhausted everyone's spare time. It doesn't mean that Google forces everyone to work all day long, but because there are too many interesting things in Google, brad often says, "Now there are seven projects that belong to 20% free time ".
• Google has a great development environment, such as source code control, build system, code review tool, debugger debugging tool, profiler tuning tool, submit queues, continuous builds, test bots, documentation and all related automation tools and processes are complete. Therefore, it is easy to hack any project, submit a patch anywhere, or to anyone, and it is worth mentioning that it is easy to find the corresponding person or list to submit the patch. Generally, submitting a patch is the best way to participate in the feature discussion and express sincerity, even if your patch is faulty.

From the above, especially the 3rd point, Google is indeed the ideal environment for technicians.