To suggest we should all call different countries by the names they use is surely to deny the strength, history and development of our own language? Nothing wrong with a bit of diversity.
Our word 'Germany' comes from the Latin Germanus, used by Julius Caesar amongst others to describe a tribe of what was then Northeast Gaul. That in turn may have been derived from a Gaulish word meaning either "noisy" or "neighbour" (ironic, or what?). Teutoni (hence Teutonic) was another word used in Rome as a Germanic tribal name.
The earlier words used in England to describe tribes of the modern Germany were Almain or Dutch. Conversely, the first recorded appearance of the word 'Dutch' (786AD) is in describing Old English. It quickly came to describe the language of the Germanic peoples, then the people and then their land too, hence Deutschland etc. In English, it came to describe the Netherlands in the 17th century - when that country coalesced and became a commercial and military threat to England, and hence we needed a name for them. (And yes, I have discovered a favourite new website!...
http://www.etymonline.com/
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