The thing is that these tools generally solve the easiest part of problem space, yet paradoxically they make the novel and interesting parts much more difficult. They may pay off if your job is an assembly line banging out trivial CRUD apps, but I just don't see the real value for any reasonable scale project.
I looked at Angular a while back and while it got rid of a few lines of code, it made the necessary edges of a modern web app incredibly ugly (and truly the biggest waste of time is fighting with your framework). That's one of the reasons I like Backbone's minimalism -- it is more a simple toolbag and less an all encompassing solution that relieves you of any reason to make decisions. Backbone also works very well in a non-pure client-side web app, which are much more common.
Seeing these comparisons I am increasingly getting the impression the discussion is dominated by people procrastinating from their projects, argue over the number of lines of "boilerplate" necessary to create an iterator, which is something that will have negligible significance later on.