They US just kept the name the discoverer wanted instead of giving into those British asshats that just wanted to troll Sir Davy.

It probably wasnt really a willful defiance thing. It's likely more correct to say that we kept the name because by the time they changed it officially in Europe, we had millions of students across the country that had textbooks with the name Aluminum in it, that had already been taught the original name, and if the inconsistentcy was even important enought to consider "correcting", it was likely deemed too costly and too much of a headache to change at the time. By the time people were buying reprints/new editions/more recently written textbooks anyway, professional chemists in the US had been calling it Aluminum for years. Given how isolated we were from Europe in the early 1800s, there was very little pressure to align with them on it, and so it stayed. The longer it stayed the more likely it was to be permanent, and here we are.

But yeah, Sir Humphrey Davy was an indecisive wishy-washy namer of elements, disseminated multiple names across the world, but somehow that is our fault when we just stuck with the one we were given and everyone else changed over nitpicky conventions. It's not the only thing that Brits shit on about American English that is entirely their invention or their mistake:

• "Soccer" being a British term short for "Association Football"

• The season "Fall" being a British term shortened from the phrase "The Fall of the Leaf" and directly complementary to "Spring" which comes from the phrase "The Spring of the Leaf", which they still use despite making fun of Americans for "Fall" instead of their "Autumn", which Americans also use.

• "Dove" instead of "dived", "pled" instead of "pleaded", "have gotten" instead of "have got", etc. all started in Britain but were dropped there and stayed in the US.

• "Herb" being pronounced with an audible "h". The word is borrowed from French, where the h is silent, exactly like , "honorary", and "honesty". Neither country pronounces either of those words with an "h" sound, but that doesnt stop people like Eddie Izzard shitting on how Americans say it with a silent "h" despite the American pronunciation being, arguably, more correct given the word's origins.

Side note, it is crazy how many words in English are borrowed from French, even if they are horribly mangled and unrecognizable now in a lot of cases. The British Aristocracy really had their noses shoved firmly up French asses for a lot of their history in the last few centuries.