Some anglicisation is inevitable, such as in cases where the names really do incorporate sounds which are foreign to English. (On the other hand, cf. Bach.) But a lot of time, the shifts are needless and driven more by Americans' ignorance of phonics than anything else. For instance, one of my grade school classmates had the surname "Konieczny" which she pronounced "kuh-NEE-zuh-nee". This is no easier to say than a far closer approximation of Polish [kɔ'ɲɛʈ͡ʂnɨ] such as "kuhn-YECH-nee" and didn't really make her life any easier, since she was forever telling everyone how to spell and pronounce her name as it was.