Why can't the English teach their children how to speak?

Something that has been putting my back up lately is how some people seem to think that the English language is being used and, to use one persons words ‘degraded’, by the use of expressions such as ‘basically’ and ‘like’. I was reading an article in the newspaper and the comments of some readers and was astonished at how some people thought certain words were incongruous with English because they used both Latin and Greek prefixes and suffixes, they are overused, young people use them more and, probably, because they don’t like them or understand them!
Why shouldn’t English speakers be able to use words that aren’t ‘proper’ English, such as ‘over-exaggerate’, ‘detrain’ or ‘diarise’? Just because these words are new to some people, don’t fit Latin grammatical rules etc. doesn’t mean that people shouldn’t use these words? Any etymologist or linguist will tell you that language evolves as time goes on and that the variety and complexity of a language is only added too by the creation of new words and the adoption of colloquialisms.
Furthermore, one of the specific beauties of the English language and one of the main reasons many believe that has led to its widespread popularity is because of its casual structure and lack of regimentation. Because English has been mangled and used differently in many countries, we have a richness and diversity that allows us to express ourselves in millions of ways. We can identify between house and home, black and dark and many others, mostly because we have allowed the language to develop that way. One of the most famous writers in literature, Shakespeare, is thought to have coined over 600 words, and that is a conservative estimate. These include:
- accessible
- fashionable
- priceless
- assassination
- crucial
- successful
- useless and useful
- impartial
- and vulnerable

So how can people say that the English that we are using is not the Queen’s English, doesn’t work grammatically, or is just not ‘correct’ way of talking? And if anyone tells me that I should speak properly and not use words that aren’t in the OED, I think I might just make the aware that one of the best new words we have in the English language is moron!