The just is FB added a clause that if you sue them and use their stuff, you immediately lose the license. So they could counter sue for breach of contract.
Ember doesn't have a PATENTS file.
Damn it, iPhone. This comment should be above as to why React has licensing issues.
Composing components is not easy in ember. The component model in general is much less sophisticated than react or angular.
If you have time, I'd like to learn more about why you have that opinion. Feel free to leave me a reply on the article.
Can you provide any source material to support this?