How to avoid using 'this' pointer in javascript (ES5/ES6)?

According to Crockford, the best practice is NOT using this pointer due to security issues.

I found this in the Ember guide,

Person = Ember.Object.extend({
  say: function(thing) {
    var name = this.get('name');
    alert(name + " says: " + thing);
  }
});

Soldier = Person.extend({
  say: function(thing) {
    this._super(thing + ", sir!");
  }
});

var yehuda = Soldier.create({
  name: "Yehuda Katz"
});

yehuda.say("Yes"); // alerts "Yehuda Katz says: Yes, sir!"

How can this be avoided in such code situations?