I love katakana, mostly because of how the characters look. But I am constantly baffled by why certain loan words from English are constructed using certain katakana sounds.
For example, if someone asked me to say "energy" in Japanese, I would have guessed エナジー or maybe エネルジー...but definitely not エネルギー. Same with "cake": ケーク sounds more natural than ケーキ. I understand that there are clearly many cases where there isn't an obvious "best fit" for certain words, but often it feels like some loan words pick the worst or least-likely sounds.
Who or what decides what loan words will sound like? Is there a governmental office that takes part in this? Seemingly, since a lot of loan words are from English, a Japanese-English speaker would be able to best form a loan word.
Am I reading too much into this? :)
EDIT: To be clear, I don't want to come across as, "How dare Japanese not try to perfectly pronounce loan words from my language!" It's more like, "Hm. I wonder why they say it this way when it's pretty easy to make a more accurate-sounding word."
a Japanese-English speaker would be able to best form a loan word.
You're making the mistake that Katakana should reflect the original pronunciation of the language it originated from. Imagine if you mandated everyone in America to pronounce "karaoke" the original way it is pronounced in Japanese, language doesn't work like that.