It's a pretty typical western ideal if you think about it,
you come here - you speak in our language.
we go there - we raise our voice and slowly over pronounciate each word.
Almost anywhere you go on holiday or to move abroad, your practically guaranteed to run into the typical westerner at a bar or shop doing the above. It's embarrassing to see but when in another country I've yet to see, an establishment that refuses to sell to none native speakers.