1)
Why did he want to die?
1.
Radak: I should not see the evil of Yisrael. So Moshe said "Mecheni Na mi'Sifrecha" (Shemos 32:32), "Hargeni Na Harog" (Bamidbar 11:15).
2.
Malbim: They did not do [full] Teshuvah, and I caused that they will remain to be a staff to afflict Yisrael.
