If you are happy with current C++ cocos2dx why not just stay with the current cocos2dx releases? Why migrate to another similar framework? I think the Cocos2dx team is doing a good job of giving more options for developers who want to use an Editor for development, or for developers who prefer JS. They haven't stopped development of the core C++ engine that we all love.
We are doing the extra work of moving to JS because it gives some advantages in development/maintenance time/cost. And makes it possible to target more platforms that need html/css/js apps. Where this is not the case, we are continuing with cocos2dx C++. Moving to another framework is just too much work with no benefits.
I love C++ and Cocos2dx, but I am not biased against other languages or frameworks. Some of our projects are using ThreeJS while others are going to stay Cocos2dx C++. Most of them are now Cocos2d-JS, and we are 'trying' Cocos Creator for one. It really depends on the project and its needs.