I disagree, I think it is the browser's job to get out of the way as much as possible. That the browser provides you shortcuts shows that it thinks of itself as being more important than the websites it renders (Opera knows Web APIs and chose to implement a feature that butts heads with one because it's rarely used).
Boppreh said he or she configured Opera to use those keys, are you suggesting that a browser ignore user configuration to better "get out of their way?".
If so, I strongly disagree with you. But I would agree that a browser's default configuration should be as unobtrusive as possible --but when configured it should meekly obey and not let websites act against your expressed will.
The browser is more important than the websites it renders, up to where preferences are concerned. Would you like websites to override your pop-up blocking preferences?
No, but that's a security preference, I don't want the browser overriding well-known Javascript APIs. Here's another example: Firefox for Android uses a swipe to the left to get to your tabs and a swipe to your right to get to favorites/navigation controls. This means that any site that uses swipe gestures for UI are broken. Google+ doesn't work on Firefox for Android for this reason. To me this is browser fail, not website fail.
