Any money or services you get during airline disruption is also paid for through insurance. The airlines would charge less for tickets if compensation etc wasn't required. It might not be explicitly marked as insurance but that's just because most airlines are large enough that they can self-insure. Some actuarian working for an airline has done the sums and worked out that essentially all disruption claims will be small enough that they don't need to pay Allianz or Prudential to cover the possibility. If you started up your own airline with just one plane and not a lot of cash in the bank you might choose differently, because those disruption claims could be quite a bit more than you can cover.
There's no reason why an airline couldn't offer a slightly higher ticket price that would offer this sort of cover. Indeed, it's what they do today where tickets that can be easily refunded or changed will cost more than inflexible tickets that can't be changed. Someone wanting to change their plans or cancel their tickets (in a situation where the airline is unlikely to be able to resell their ticket to someone else) is just an insurance claim like any other.
The popularity of super low cost and inflexible tickets suggests that most passengers, if given the choice, do actually prefer to take the risk if it means being able to do that travel at all. But, obviously, you then need to have a plan in case it does. The nature of air travel, and especially low-cost airline travel, makes those alternate plans a lot harder. People are generally a bit more trapped when they're at an airport. If everything were hub and spoke there'd be a bit more in-built flexibility but low-cost carriers are all about finding that there are enough people to fill a 737 return flight once a week from one random regional airport to another 3 hours away. And, of course, those low-cost fares mean any and all slack in the system gets wiped out so there's unlikely to be any spare seats at all, so the only way of getting people home is to find another plane. There are dry and wet leasing companies who would offer a 737 with or without crew at a few hours' notice for a replacement charter flight but the cost per passenger would be eye-watering compared to the £19.99 they probably paid for their original ticket.
So, avoiding the real risk of passenger mutiny at an airport might not be a bad idea for the airlines even if they could maybe eke out a bit more profit with it. I recall the problems when Monarch and Thomas Cook went bust and the CAA had to get everyone home. In principle, only those on ATOL-protected package holidays were actually entitled to this help. But, given the impossibility of getting a couple of British embassy/consulate staff to tell thousands of angry Brits in a check-in queue that they weren't actually flying home unless they cough up possibly hundreds for a new ticket, it made more sense just to treat everyone the same. The issue then is that people will expect that outcome in future, so they won't pay extra for the ATOL protection of a package holiday. Which, in turn, means that we probably need to just change the way we insure any British people travelling abroad for their holidays so that everyone pays their fair share.
Eurostar seems a fair bit closer to the hub and spoke model where self insurance would work. It's not like there's any real shortage of transport options from London to Brussels and Paris. It might be inconvenient, yes, but being stuck in the centre of a world city is hardly like being stuck at 2am at a regional airport where all the staff just want to go home and there's not even an hotel or public bus running nearby. If there were significant demand for higher fares with built-in insurance then Eurostar could just offer them.
