what's the utility of using Activator.CreateInstance method

what is the difference between these two snippets of code. I want to know why he use all that amount of code at the second snippet while he could just use simple new to create an instance of DataTable;

1) var dt = new DataTable();
2) var dt = ObjectBuilder.Instance<DataTable>();

.

public class ObjectBuilder
{
    #region ObjectBuilder Members

    /// <summary>
    /// Instances this instance.
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <returns></returns>
    public static T Instance<T>() where T : class
    {
        return Activator.CreateInstance<T>();
    }

    /// <summary>
    /// Instances the specified arguments.
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="arguments">The arguments.</param>
    /// <returns></returns>
    public static T Instance<T>(params object[] arguments) where T : class
    {
        return (T)Activator.CreateInstance(typeof(T), arguments);
    }
}