﴿ ذَٰلِكَ بِأَنَّهُمُ ٱسْتَحَبُّوا۟ ٱلْحَيَوٰةَ ٱلدُّنْيَا عَلَى ٱلْءَاخِرَةِ وَأَنَّ ٱللَّهَ لَا يَهْدِى ٱلْقَوْمَ ٱلْكَٰفِرِينَ ﴾

“all this, because they hold this world's life in greater esteem than the life to come, and because God does not bestow His guidance upon people who deny the truth.”

That threat of chastisement for them is because they have preferred the life of this world they have chosen it in preference to the Hereafter and because God does not guide the disbelieving folk.