3. Money, money, money

The evolutionary and psychological motivations of consumers might account for a large chunk of the willingness to surrender oneself to (simulated) abject terror, but there’s another, perhaps more dominant component to this equation:  the businesses themselves.

Whereas a large number of present-day haunted houses snake a never-ending human conga line through their attractions, the extreme haunts only pulse small groups – or, even, just an individual by himself – through, playing up the isolation of the experience and, thereby, its overall level of fear.  Exclusivity has long been the driving source of value all throughout economic history, and that's certainly also reflected here:  patrons must pay for this deluxe, upgraded service, starting at £3.50 for Scare Kingdom Scream Park's Psychomanteum and going all the way up to $50 for Howl-O-Scream's Experiment.

Just as Disney has been resorting more and more to hard-ticketed events (such as the recent [and much-maligned] Villains Unleashed) for an extra injection of cash from its pre-existent customers, haunt operators are turning to these extreme attractions to similarly generate new lines of income. And since most of these are add-on experiences at already-established locations, they can do so at very little additional cost – a win-win scenario for them.

4. Put simply? Because we can

The main argument levied against scientists for the past 700 years can be summed up thusly:  just because it can be done – whether "it" be the splitting of the atom or the cloning of a human embryo – doesn’t necessarily mean that it should be done. The drive behind this constant push, however, is an entirely human one; once something appears in conceptualization, it must be realized in execution, from the expansion of scientific knowledge to the construction of an attraction that pushes the boundaries of what constitutes “entertainment.”

Actually, pushing the theming threshold has been continuously attempted in one way or another for nearly as long as there has been such a thing as theme parks (and, probably, even before then), starting with the opening of the more intense Matterhorn Bobslebs at Disneyland in 1959 and going all the way to the debut of the totally immersive Wizarding World of Harry Potter – Diagon Alley at Universal Studios Florida just this summer.  Extreme haunts hit both of these points simultaneously – and despite the psychologically damaging experiences they produce, they do represent the most complete erasure between reality and show yet conceived.

If you don’t mind a bout of post-traumatic stress disorder in the process, of course.