Some would call it bloody or genocidal, but it was necessary, the Indians were a bane as terrible to the old Argentinean republic as the mongols were to the chinese, when you have multiple of your children murdered and your capital razed to the ground, innocents raped and relentless brutalizing by savages in multiple occasio s it's kinda natural you develop a genocidal hatred for them, and march on punitive expeditions to wipe them out as a threat.

The Qing did the same to the Dzunghar mongols, Amerimutts did the same to their brand of amerindian savage and the romans did the same to the Gauls. You don't want aggressive, chimping tribals right beside your civilization wreaking havoc all the time, they have to be eliminated. There's no space for barbaric savages in a propper modern, civilized, educated and cultured nation, they have to be removed.

Plus, the ensuing expansion turned Argentina into the richest country in the world for a while.