There was a bug with yo backbone with require.js
The fix is: https://github.com/yeoman/yeoman/issues/1182
Fix : As soon as I go to start creating new app. I hit ctrl+c and stopped the process. Then I went to the package.json file which is created and updated it based on this stack overflow discussion asciidisco/grunt-requirejs#65
“grunt-requirejs”: “*”, to “grunt-contrib-requirejs”: “*”.