Hey, we're told we aren't guaranteed the seat on our ticket, we're not guaranteed the type of plane we purchased the ticket for, we're not guaranteed our preference in food. I don't think it unreasonable they can at least try to make sure we've gotten on a plane heading towards the destination on our ticket.

If we have to get serious about this, things can get confusing at airports, with gate changes, plane changes, delays etc. And how many of us haven't at some point arrived at an airport in a state one level above or below zombie?

Even though the passenger does have some responsibility (a lot of responsibility, actually) to navigate themselves through the airport and onto the right plane, there are so many ways for the airline to catch someone who's in the wrong place at the right time that I suspect they (the airline) would be as embarrassed about things as the passenger, and the mutual state of embarrassment would result in as pleasant-as-possible parting of the ways. Everybody apologizing, no hard feelings, passenger ends up where they're supposed to and if an overnight is required, a hotel voucher is kindly supplied. Smiles all around in the aftermath. No compensation per se but lots of goodwill by all parties.