Americans make a lot of mistakes period, spelling and otherwise. But ours is an experimental society. Sure we speak English, but not like the English do. We pronounce words differently and we spell some of them differently too. Gray, not grey; check, not cheque; color, not colour. We also change our spellings over time: it is now sulfur not sulphur, so why not fone instead of phone? Or do we all have to call it a telephone all of the time?
American English is also one of the most complicated languages. We tend to borrow more words and phrases than any other language and we also tend to make up new words for the rest of the world to use. Television, transistor, vulcanization, teflon. The list is a long one. In addition, we have some of the strangest idioms, because we come from all over the world. Many Americans speak English as a second language. We are very diverse.
This is not a matter of a failure in education. Sometimes the professional educator is too conservative for young modern minds. And remember that until the advent of the press and the first dictionaries published by linguists, spelling was not taught as a subject. Everyone spelled as they wished, and often used different spellings for the same word used more than once in the same document.
Americans were the first to even attempt to teach spelling to all of their citizens on a mass scale. No other country can make that claim, not with numbers of students as large. Is it any wonder that some of these do not spell well?
What is more confusing is that we tend to type like we think except that we do not type very well. The more excited we get, the worse the mistakes and many do not bother to check what was written.
As a final note it was also the Americans who developed the first spell checker programs (going back to the days of the CP/M operating systems in the late 1970’s). Not bad for a pack of mongrels, semi-educated and with no cultural roots. Ah, did I mispel anything?