Out of curiosity, why did Opera not disable this change?
Because it wouldn't make sense? If they would be changing Chromium all the time, there would be no meaning in using it.
There are many unhappy campers because of this.
Yes it can be resolved in Settings, but why annoy so many users?
Well, the key was disabled because the previous behaviour was annoying many users. So i guess the other side won this time.
Basic users don't even know about these forums or settings. They just want a browser that goes back a page when they press the Backspace key.
Average users most probably don't even use the keyboard to navigate.
Correction. There is no problem with the developers' team. The problem lies with uneducated users who refuse to read their blogs and bring themselves up to date on what Opera has been doing for two years now and will continue to do. If you want to see some favorite feature put back into Opera, go over to the Suggestion Box and add it there... respectfully... not demanding and threatening and behaving like spoiled children. If you find the new browser does not meet your current needs, use Opera 12 and keep an eye of the new browser's development rather than rag on the developers' team. You did not pay for the browser. You did not sign any contracts for the browser. You were given free use of it along with free technical support and the company does not "owe" you anything... particularly if you make petulant demands.