The main and only real reason that commercial aircraft have to make an emergency descent when the cabin pressure is lost is simply because they have passengers in the back!
The drop-out oxygen "should work" and those punters who have actually taken the trouble to listen to the pre-flight safety briefing instead of reading the oil futures in their FT will be able to select a pretty basic piece of breathing equipment from above their heads. This will keep them alive while the crew get them down to 10,000ft in about 3-4 minutes.
Sadly, a small percentage of the masks are likely not to deploy as advertised. If it is a real structural problem then there could also be a certain amount of fog, dust and s**t around the place at which point "well-travelled-and-don't-need-to listen" FT man starts to wish that he had listened and looked during the briefing!
If you have an ear problem then you simply should not go flying. (In fact, the first 1000 feet on the way up is the real indication of a problem).
No crew does an emergency descent for fun! Certainly it would be a considerable embarrassment at 30°W. Not many airlines carry enough fuel to complete such a journey at 10,000 ft with full reserves. (Even at 14,000 ft with the equivalent of single-pack operation it is likely that your relieved punters will spend a fortune in the Duty Free in Shannon instead of "grumbling off" at Heathrow or Manchester).
Happiness is freight - I can stay up there without a single worry for I shall run out of fuel long before I run out of oxygen!