Considering Benjamin Franklin in other writings has shown a much more enlightened view of Indians, this passage you quoted might have been written with sarcasm and this is an earlier example of Poe's law. This passage has more to do with the virtue of temperance and rum than indians. This passage is more like objectively talking about how the CIA worked to help import cocaine in the United States in the 80s and how African American communities like Harlem were being destroyed because of the crack epidemic because of these policies of the government.

This passage edited for 2019 internet should read.

'The next day, sensible they had misbehav’d in giving us that disturbance, they sent three of their old counselors to make their apology. The orator acknowledg’d the fault, but laid it upon the rum; and then endeavoured to excuse the rum by saying, ”The Great Spirit, who made all things, made everything for some use, and whatever use he design’d anything for, that use it should always be put to. Now, when he made rum, he said, ‘Let this be for the Indians to get drunk with,’ and it must be so.“

And, indeed, if it be the design of Providence to extirpate these savages in order to make room for cultivators of the earth, it seems not improbable that rum may be the appointed means. It has already annihilated all the tribes who formerly inhabited the sea-coast.' /s