If having more words makes a language richer, then words pronunced the same but spelt differently should apply as well. After all in English the words metre and meter mean two different things as do the words tyre and tire. So if adding to the language makes it richer then doesn't the opposite apply? In regards to English, remember the saying that "Britain and America are two countries divided by a common language". As for English itslef it does love to borrow words from other languages.