For most generalists who doesn't live in the frontend, learning every framework and applying the right one is not tenable. None of the js client-side MVCs I've

For most generalists who doesn't live in the frontend, learning every framework and applying the right one is not tenable. None of the js client-side MVCs I've seen are easy to just pick up. Even 6 months after I haven't used one I have trouble remembering how it works. You'll be much much more productive on something you are familiar with, even if it's not an exact fit. If you are a frontend javascript consultant, than by all means, learn them all.