[SkeuomorphicBee]

Your mundane explanation misses the main point that perfect security can't exist while maintainint function. It is not just a matter of cost cutting, it is a (sort of) fundamental law that security and usability are opposite ends of a spectrum, at the limit any gains in security can only be achieved by a loss of usability. So any system that is perfectly secure will be perfectly unusable, or in the business angle, any system with 0% fraud will have 0% sales.

[mjw_byrne]

I'm not sure this is true in principle though. For example, there's plenty of encryption in use today that has "perfect" security (in the sense that a cipher hasn't been broken) and which is transparent to the end user. This wouldn't have been true a long time ago, when there was no such thing as computer science and the security of information was more to do with how many soldiers you had and how beefy your strongbox was.

Similarly, there's no reason in principle why certain classes of fraud couldn't be rendered practically impossible by an advance in technology, which would undermine the whole "you should welcome some fraud" argument.