Around the world students are learning English, and due to the fact that England has had a greater impact on the world than America, in terms of English language learning, more countries learn the British spelling, pronunciation, reading, and culture.
America should not stand apart from the global society.
As Americans travel to other countries, and foreigners travel to America they must adapt to a new style of reading, due to the differences in spelling. This makes it very difficult for English language learners to learn the language efficiently. It is not rational to ask students to learn two, or more, spelling systems of the same language. This ultimately causes problems with reading and reading comprehension.
From region to region, country to country, each has an individual language and dialects, even in Britain people speak quite differently from Scotland to Liverpool to London.
Its interesting how many British words have evolved into different spellings in American spelling, I mean English takes its spelling from so many sources like French, Latin, German etc.
I like the differences between American, English, Australian, people don't need to fit into boxes and speak a certain way, you can make up a word and use it freely, I like that.
And it doesn't really matter, sidewalk or pavement, realize or realise etc, you know in the UK depending on the region there are around 20 different ways to say bread bun :) all spelled different.