That is because they preferred the worldly life over the Hereafter and that Allah does not guide the disbelieving people.
ذَٰلِكَ بِأَنَّهُمُ اسْتَحَبُّوا الْحَيَاةَ الدُّنْيَا عَلَى الْآخِرَةِ وَأَنَّ اللَّهَ لَا يَهْدِي الْقَوْمَ الْكَافِرِينَ
That is because they preferred the worldly life over the Hereafter and that Allah does not guide the disbelieving people.
ذَٰلِكَ بِأَنَّهُمُ اسْتَحَبُّوا الْحَيَاةَ الدُّنْيَا عَلَى الْآخِرَةِ وَأَنَّ اللَّهَ لَا يَهْدِي الْقَوْمَ الْكَافِرِينَ