Skip JSON format in rails generate scaffold
Comment out gem jbuilder in your Gemfile and respond_to blocks won't be generated.
Just clone the file
to your
lib/rails/generators/rails/scaffold_controller/templates/controller.rbpath in your application and customize what you want. Also, you can write your own generators for scaffolding ( http://guides.rubyonrails.org/generators.html ).
I think you'd be missing an opportunity. For one thing, you'd be teaching non-standard Rails, so your students might be confused when they see the normal version in their own installations.
More importantly, the controllers are formatted that way for a reason. Rails puts an emphasis on REST, which encourages access to resources via multiple data formats. Many modern apps are de-emphasizing slower server-rendered html/erb responses in favor of json APIs. I realize this is a little over a year after your OP, and you have limited time in class, just adding some thoughts for anyone who might happen by. I think you could wave your hand over the respond_to and tell them it's setting you up for some future possibilities.