sure and that's valid
but it's not nintendo (or publishers, or whatever) saying "oh, all americans are dumber! they don't understand x and they actually think y!". It's closer to "well, we'll sell more if we do x and we'll maybe have less controversy if we do y, generally speaking amongst this market".
larger factors: industry bodies, retail partners and their ideas about what they want to stock on shelves, organised pressure groups etc.
but according to some every localisation change is a company personally telling everyone that you can't handle boobs. i dunno.
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changes to story and lack of dlc suck ass (though, personally, I never see the upset in changing ages in games). it is funny we've come around to begging publishers for dlc tho.