Clearly, reformer Americans like Noah Webster where unhappy with the Mother England and wanted their own identity, and part of that was to screw with the English language to piss off (a term that makes no sense either, but I love it.) ya'll in England. It has worked it seems.
I can see how the English are irritated with the bastardization, and slang of the American language. Very much in the same way as you pointed out with our slang, i.e. Wasssup. The American language unlike the English language was greatly influenced by African slave code, and the evolution of that. The immigrant English, Scottish, Irish, themselves. As well as other immigrants especially 1800's to 1940's. American language and it's slang was influenced by criminal code as well. Even old Cockney Rhyming slang is still in use today as American common expressions and slang. Take for example, an old term I use to use and hear, 'pony up.' meaning as we use it to pay moneymeaning to pay up or make good on an obligation, comes from the word
pone which is derived from the Latin
ponere, to seize. Which a few years ago, pony came back into vogue as 'pwned' (poned), relating to being pwned- being defeated by another. That was popularized by the youth. Yes, I can see how it irritates the Brits. I see it like the youngest sibling annoying the older one. The whole affair is humorist, i.e. when I really thought of how 'metaling' was heard as meddling, tickles by dry sense of humor.