Why Ubuntu Tweak Development Stopped?

Tualatrix Chou, developer and maintainer of awesome customization tool Ubuntu Tweak recently announced that he won't develop Ubuntu Tweak anymore.

Below are some excerpts from his announcement:

No matter how you got this news, what I want to announce is the same: I want to stop the development and maintenance of Ubuntu Tweak. This means you will not be able to use “Apps” (Since it is a web service), I will not response for the bug report, the last commit of the code will be: Add cache support for Apps, only available in Ubuntu 12.10, so sad…

You may ask why I made this decision to stop the development of Ubuntu Tweak, I may write 10,000 words to describe how I start this project, how I feel happy from this project, how I feel bad from this project…But I just want to say:  If making free software is not free any more, why still doing this?

He didn't clearly mention the reasons for his decision. There are over 150 comments on the blog post where Ubuntu users have expressed how much they love Ubuntu Tweak.

Now, Tualatrix Chou's friend CS Slayer has explained possible reasons for his decision. He said Chou feels that developing Ubuntu Tweak is depressing as it can never make into official Ubuntu source. Chou has made some changes to cut down some features so that Ubuntu Tweak can be included in Ubuntu, however it seems they are not enough. May be because of this he feels that making free software is not free any more.

Chou has now tweeted that he will make a new announcement by the end of this weekend.