I still don't understand why people put up with it. If I was on a plane, on the ground, for more than a couple of hours without being fed, watered and entertained then I would just walk off it. If I had to I would blow the slides to get off.
Yes, they'll probably arrest me but nothing will come from that in the UK. And I'm sure large numbers of people would follow so it is unlikely that they would even arrest.
Don't put it up with it and it will stop happening!
There's always one!
Ok, James 1077. Let me add a few more scenarios to those already given by ExXB. There you are. You've diverted and you're a little disgruntled but not expecting too much of a delay. As you pull onto stand, in the background, a PA is made. "Cabin Crew, doors to manual and cross check." As a regular traveller that has heard some version of the above many times, it barely even registers on your radar.
Now fast forward four hours. You are way more than disgruntled and you know your rights! No one is going to keep you on an aircraft against your will. So up you jump, declaring, "If you won't let me get off, I'm going to blow the slides and get off that way!" Other, equally disgruntled passengers, start to cheer and follow you down the aisle. You are a hero! You have taken charge of the situation. As a certain ad would say, James, you are so mo**y supermarket! So you fling open the door...and look down into a gaping great hole. Remember that PA all those hours earlier? Sadly, those behind you can't see that there is no slide. So they keep pushing and out you go.
But lets say today is your lucky day. For some reason, the doors are still in automatic and out pops the slide. Sadly, it's not such a lucky day for the poor ground staff member that happens to be standing underneath when that slide comes down. Or maybe it's her lucky day too. But not the best day for the honey wagon, which is just pulling forward. Trust me. You do not want to slide down onto the honey wagon.
However, unbelievably a small part of your mind has retained a modicum of sense and you have checked outside to see that nothing is blocking the slide. (Unlikely but possible, I suppose.) Have you ever stood at the top of one of those slides, looking down. They are high. And very steep. All of a sudden, you're not feeling like much of a hero. But no time to stop! Everyone is coming down behind you, don't forget. And best make sure you get away from the bottom of the slide quickly. But as ExXB has already said, be careful not to run in front of that taxiing aircraft....
I'm sure you get the idea by now. So please can we drop this "I'll blow the slide" attitude once and for all? Those slides are there for one scenario and one scenario only. When the situation in the cabin is so bad that your life would be in immediate danger, were you to stay. They are not playground slides and injuries will and do happen. They are certainly not there because you want to make a point!
Going back to the actual incident in question, I'd be interested to know whether the airline made any requests for the passengers to be allowed into the terminal at least. Obviously, with some passengers possibly connecting directly onto other international flights from LHR and therefore not having UK Visa's, they would probably have had to stay airside but as others have said, at least they would have had access to better facilities or even the chance to stretch their legs. For those that know about ground operations, could the airport refuse to allow the passengers into the terminal? In other words, once they accept an aircraft into their airport, do they then share some responsibility for duty of care of the passengers with the airline? And if not, why not? True, it's not their fault if an aircraft has been diverted into their airport due to bad weather, volcanic ash etc but it's not really the fault of the airline either. In no way am I trying to shift the blame from AI as undoubtedly, they got it wrong but it does always seem to be the airlines that have to pay while the airports get away with doing the bare minimum.