Because it's full of nastiness they can relate to, I expect. Like, oh, being imprecated to dash out the brains of their enemies' babies against the rocks. Suits the Southern Baptist mindset, that sort of vengeful behaviour.
(Psalm 137 verse 9, if people want to check.)
The later bits where God is specified as saying things like "Vengeance is mine; I will repay" tend to be overlooked a bit.
As for instance Romans 12, where it says
17 Recompense to no man evil for evil. Provide things honest in the sight of all men.
18 If it be possible, as much as lieth in you, live peaceably with all men.
19 Dearly beloved, avenge not yourselves, but rather give place unto wrath: for it is written, Vengeance is mine; I will repay, saith the Lord.
That's too modern for the Bible-thumping MAGA. That's why they cleave to the older books. Turning the other cheek is not something they want to consider.