When I was hired to work on the Angular 2 team, I was told one thing about the project, but as time progressed I realized what I was told and what I was asked to do did not align with what was happening internally. I realized that Angular 2 was not something I wanted to use, not something my community wanted to use, and probably wasn't something that much of the Angular 1 community would want to use (if they knew everyting I knew). So, I left the Angular 2 team to build a next generation platform based on adherance to web standards, designed to solve the real problems that developers face in the real world. I found out that much of the Angular team had little to no experience building apps even with their own framework and just didn't understand the challenges faced by developers. I had 10 years of consulting experience in the front-end and front-end frameworks and felt I could help people address their issues based on that experience.
Bottom line is that there are real problems and challenges that the Angular team was not addressing but that I Aurelia could.