"Friday the 13th Strikes Again-Two Months in a Row"!

In his article, “Friday the 13th Strikes Again-Two Months in a Row” from the National Geographic, John Roach claims that the number thirteen is getting falsely called an unlucky number since it comes after a complete number, 12. The reason we have at least a minimum of one Friday the thirteenth or a maximum of three Fridays the thirteenth in a year is because we follow the Gregorian calendar. This year we have three Fridays the thirteen: February 13, March 13, and on November 13. According to Fernsler, numerologist consider 12 a “complete” number because there are “12 months in a year 12 signs of the zodiac, 12 god of Olympus, 12 labors of Hercules, 12 tribes of Israel, and 12 apostles of Jesus.” So thirteen is associated with bad luck because it comes a little beyond completeness. People have become so superstitious On Friday the thirteen many people refuse to fly, buy a house, or do anything important on that day. It has been estimated that the U.S. loses $800 or $900 million in business on Friday the thirteenth because people will not fly or do business that they would normally do. It has been estimated that 17-21 million people in the United States are triskaidekaphobic or fear Friday the 13. The fear of 13 is shown in society: 80 percent of high-rising buildings lack a 13th floor, many airports skip the 13 gate, and hospital and hotels regularly have no room number 13।Roach suggests that the number 13 is just a normal that the myths and the people have made unlucky.
Questions
Application: Why are people so fearful when it comes to Friday the thirteenth? Why can't people treat it like a normal day.
Style: Does the author's sarcastic yet serious writing style make the author seem indifferent to the people's superstitious beliefs?

Link: http://news.nationalgeographic.com/news/pf/75333841.html