Fun fact: Qiang Xue got his PhD at Duke University and developed Yii2 while living in the D.C. Area by leading a multi-national team of core contributors, the top 3 being from Germany, Russia, and Ukraine.
He also moved on from the project mid-2015 and the other maintainers have run day-to-day operations since then. It's not a "Chinese stack". I've read the source and issues extensively and it is high quality code that welcomes high quality contributions - no matter where people are from.