cause Nintendo's marketing team ****ed up big time by a) marketing the game to kids way younger (iirc it was like 8-10 year olds) then it should have been and b) making the game's marketing all about how the game "stinks". I'm sure the US would have loved EarthBound if they had marketed it right. Even if you do have a $10 off coupon, and get a free guide, if the game "stinks", I don't know about buying it...
Now NOA hates EB cause the marketing budget was like $2 million and there were only a few hundred thousand copies sold...
Pokemon could have easily ended up the same way as EarthBound. At first they wanted Clefairy to be in Pikachu's "mascot" position, following Ash and everything. CLEFAIRY. Wait, one more time, think about it... ****ING. CLEFAIRY. And the NA localizers wanted to "buff up" the Pokemon cause they thought the US wouldn't like em cause they're too cute.
But I digress...