That is because they are saying: “The fire will never touch us except for numbered days”. They have been deceived by the self-invented forgeries in their way of life.
The addresses of this verse were the Jews and Christians during the time of Messenger in Medina. Today the Fujjar who hide and reject Adhikr and differentiated into various groups are having this worst character among mankind. If they are called to Lord’s Book Adhikr, they will not accept It. They don’t utter any of the forty names of Lord’s Book to mankind. Instead, they will only utter ‘Quran’ which only means ‘For repeated reading’. They are compared to that of a dog which doesn’t change its attitude whether it is disturbed or not as explained in verses 7: 175-176. They will be in the shape of a dog with yokes in Hell as told in verses 40: 69-74 and 76: 4. The Messenger and believers are commanded to ignore the Fujjar as told in verses 53: 29-30. These Fujjar are guessing that even if they are entered in Hell, by the intercession of Prophets and others they will be raised into Paradise within days. These Fujjar will wail in Hell as: “If I hadn’t selected so and so as my intimate friend, he led me astray from Adhikr after It had come to me; nay, Satan was a traitor to mankind” as told in verses 25: 28-29. Messenger Muhammad will come with Adhikr to witness against these people as: “Oh my Lord, indeed these people of mine have migrated away from this Reading”. The Fujjar will argue, curse, and blame each other in Hell as explained in verses 2: 165-167. See explanation 2: 80, 94-95, and 5: 10.