> English has a long tradition of stealing words from other languages then mangling them almost beyond recognition because we're too lazy to take efforts to pronounce them correctly. To me, this is a form of language arrogance.

First, there is more than one English: British (plus England, Scotland, etc), American, Australian, Indian, etc.

Second, each language has its own way of doing things, and so words would be pronounced according to the rules of the context of the language that is being used. Should the Japanese pronounce "tempura" the way the Portuguese do, given that the Japanese got the idea from them? Or should a Japanese speaker pronounce it "properly" for the Japanese, and a Portuguese speaker properly for that language?

> So often one hears TV newsreaders including those on the BBC slur the word as 'sooonami' when clearly its English spelling indicates the correct pronunciation. Tsu, つ, sounds like a hissing snake—say it to yourself. Is that not obvious?

Welcome to the world of accents.

Also worth considering that the fact that English does not really care about accents (or tones) to convey meaning helps non-native speakers use it. Two ESL people can probably communicate well enough to get messages across. (Probably handy for English being the modern lingua franca.)