I have no evidence to back this up, but I suspect more and more developers are moving to Symfony2 due to the glacial pace of Yii development.
Yii v1.1 was released in January 2010. In the following 3.5 years, there have been many changes in the world of web development - namespacing and traits in PHP, AWS-style hosting going mainstream, JavaScript MVC frameworks - and Yii neither takes advantage of them, nor makes it easy for you to take advantage of them.
It's a shame, but unless they have some revolutionary idea, Yii is probably dead in the water.
Don't they still have speed going for them? Last I read, Yii was often considered the fastest and least cluttered of the PHP frameworks? also, on a personal note, I use it and I like it.
Yii v1.1 was released in January 2010. In the following 3.5 years, there have been many changes in the world of web development - namespacing and traits in PHP, AWS-style hosting going mainstream, JavaScript MVC frameworks - and Yii neither takes advantage of them, nor makes it easy for you to take advantage of them.
It's a shame, but unless they have some revolutionary idea, Yii is probably dead in the water.