Thus the quicker option (i.e flying) is always going to be more expensive.
No, that's not right. Slower ships cost considerably more per mile. It's because the perceived value of time (saved) has a value and that can be reflected in the ticket price. Another factor is route competition. We flew NCL-FAO. There was none given the timings and the package offered. The price of a ticket has little, if any, bearing on cost.
If you would have booked your flight when you saw that fare, you would have got that fare!
Wrong. You are clearly ignorant about your company's product marketing channels. We bought our flights via Villa Plus and they have to buy their customers tickets during normal working hours - not online. We booked and paid our deposit to confirm our booking on a Friday night and got chiseled by EasyJet on Monday.
There are other airlines who fly between LON and FAO...
So? We flew from NCL and believe me, in the future I will try and fly with someone else if I can.
£0.15 per seat mile is still very cheap.
At that rate, you can fly with a 'legacy' carrier like Qantas or BA, have meals included, allocated seats etc and still have a few pence per mile to spare.
It's obvious that you have bought the illusion of 'low cost'. 'Low Cost' means that very little is included in the price of your ticket other than a random seat on a flight. If you want anything else you'll have to pay for it, often through the nose. However, the basic fare will be the maximum the marketing gurus reckon they can get away with, not the least they can charge and still make a profit.
I am not unpleasant onboard and I am very professional in my work.
I'm sure you are. We can see that by your argument.