Might be biased here as a Braves fan, but isn't an brave a good thing? It symbolized strength and that you were a warrior for the tribe. In order to become a brave, had to perform an act of courage on behalf of your tribe.
Plus, the Braves got their name because their owner (in 1912) was James Gaffney, who was a "brave" of Tammany Hall, NYC's political machine at the time. Members were called "braves" since Tammany Hall's symbol was a Native American headdress.
And, perhaps most importantly, it was a different time. People had different opinions and values in the late 1700s when Tammany Hall was founded and even in the early 1900s.
"Perfection is not attainable, but if we chase perfection we can catch excellence."
-Vince Lombardi