I've worked in a number of other commercial areas and there are just as many errors made there too, by customers, agents and own staff.
Aviation seems unique in its ability in these situations to enjoy stiffing their revenue source, their customers, for not being completely in compliance with their complex requirements. There is a desire to pocket the money the instant it is paid and never, ever, to return it, and also to grossly overcharge for making any corrections. Elsewhere it is just one of those things a business needs to sort out as part of day-to-day life.
The British pax who booked on a website to Sydney in Canada instead of Australia was a good point. How could anybody be so stupid ? Well, if you looked at the website of the major booking agency they used, in the list of destinations they were not shown as "Canada" and "Australia", but as Sydney NS (for Nova Scotia) and Sydney NSW (for New South Wales). And so instead of writing in plain language, things were reduced to industryspeak. The confirmations likewise came also saying just Sydney NS and YQY, no mention of any country. And then the industry laughs at those who may get confused.