Sometimes lack of knowledge in JS kills and this is why

gistfile1.js

$(document).ready(function(){
  console.clear();
  console.log('STARTING THE TEST');
  var wrapper = $('#wrapper'),
      enabled_1 = Boolean(wrapper.attr('data-feature-enabled')),
      enabled_2 = Boolean(wrapper.data('feature-enabled')),
      enabled_3 = Boolean(wrapper.prop('data-feature-enabled'));

  console.log(enabled_1 + ': expected false');
  console.log(enabled_2 + ': expected false - correct'); 
  console.log(enabled_3 + ': expected false - correct? No! See bellow why.');
  console.log("wrapper.prop('data-feature-enabled') is "  + wrapper.prop('data-feature-enabled'));

  console.log('TEST END');
});

/**
 * This is what the console outputs:
 * "STARTING THE TEST"
 * "true: expected false"
 * "false: expected false - correct"
 * "false: expected false - correct? No! See bellow why."
 * "wrapper.prop('data-feature-enabled') is undefined"
 * "TEST END"
 */