Well, we cannot assume that people cannot learn. Snippets are smaller piece of codes compared to controllers, and logically making more sense. All you have to do is to train people. Isn't it the way people learn MVC too?
I respectfully disagree. I was able to finish an ajax form, including value validation with only a snippet and it's binded scala function. I did not have to create a specific rest API and write up jquery ajax code along with the snippet.
Lift's JS & Jquery support was never meant to replace js and jquery. (don't write up every js feature with lift.) It's meant to eliminate tedious js works that both frontend and backend developers don't want to spend time on.