Preflight is nothing more than a quality control process. Are we really arrogant enough to believe that we do not need to quality control check the raw materials (art) coming into our manufacturing plants?
As a manufacturer you need to control the quality of the raw materials (art in this case) that you bring into your plant. Imagine an ink manufacturer just bringing in pigment and oil (and whatever else they require) and making a thousand pounds of process cyan ink. Probably wouldn't be a very consistent product. So they take samples of the pigment, the oil and the other components to ensure that they meet a minimum defined specification. It doesn't matter what the specification is, just that it is met. Now they have a bit of process control which allows them to more consistently produce a product of some defined level of quality.
For our industry (and related) there are two basic preflight types; technical and mechanical. A technical preflight software can make more efficient. The mechanical preflight a person really needs to evaluate the art to determine its suitability. A human can determine for their press(es) that a ghosting bar is needed, or they need to run this a certain direction, etc. A program can look and see if the colors used meet the specification, spot vs. CMYK possibly. If the image is too low resolution, rich blacks are used when they shouldn't or aren't when they should. A whole host of conditions can be checked by software.
Preflight isn't really meant for the "average person". They do not know the manufacturing specifications and cannot be reasonably expected to. We know the limits of our equipment and we are expected to produce a quality (what ever criteria is used) product. So it is our responsibility to check the quality of the incoming raw materials. If there's a problem we need to alert our supplier (the customer) and somehow or another resolve the issue. This is where we can be pro-active and maybe even generate a little money. We know the geek speak and the customer doesn't. We can use a technical preflight tool like callas pdfToolbox Server, PitStop Server or FlightCheck to generate a report that can be understood by us. We can similarly use an application to translate a technical issue into something more human friendly.
Apago had the best idea, a thumbs up or a thumbs down. And they did this back in 1999 I think it was with their PDF/X Checkup. If it met PDF/X-1a requirements then you got a thumbs up. If you didn't then you got a thumbs down. It said you have color spaces not allowed, you have an art box when you shouldn't, etc. Really stupid simple. Markzware, Enfocus and Callas have similar ideas but with a lot more possible reasons. They've got green check marks or red X's to give a graphical pass/fail indicator.
Everyone comes up with various conditions that must be met for a variety of reasons. What is a meaningful diagnostic result for one company/person is superfluous for another for what ever reason. There are all sorts of criteria that we use to judge the quality of the raw materials all of which have some impact. There are also limits to what we can practically diagnose. For instance I can use software to check if any object (or a specific kind of object) crosses a page box in a particular direction (an object extends beyond the trim box) or an object extends beyond the trim box and lies within the bleed box. This tells me that something is there. But not necessarily *what* is there. Nor does it tell me if it should be there or if it is at all usable.
So yes, to a certain degree this is rocket science IF you are programming a tool to diagnose a document. It can also be rocket science if you want to generate a very thorough diagnosis as a user. It can be presented as a very technical diagnosis to the end user (supplier in our case). Imagine reading your doctors lab report and trying to understand it. You rely upon them to translate it into something meaningful to you. "Your glycemic index is y, your HDL/LDL ratio is 1:1.3, your t-cell count is z (I'm just pulling these out of the air). What the heck am I supposed to do with that? Tell me "you've got diabetes, you bad cholesterol is too high and it's hard for you to fight infections". Similarly we can use all sorts of technical means to diagnose a piece of art and give us a laymens interpretation either through software or a human. I've helped set up look up tables for a specific reported error which can be substituted by a human friendly interpretation. "Your TAC exceeds 245% for an area of .375". Hmm... Okay WTF? How about "There is too much ink in dark portions of your art, we need to fix that". That's not quite so much rocket science is it? So now it's not so much an issue of reporting but usability. All the tools don't do quite so good of a job of giving a usable result when you say "the average PERSON". For a printing professional it's just fine.
We can build processes that say "your business card is not the right size, there is some print that is too small and you are using colors we can't use." Where the machine is actually saying "the trim box does not equal 3.5 x 2, uses type that is less than 7 pts, ICC based RGB is present, spot colors do not use an alternate color space of CMYK or device gray".
The technology exists to enable us as print providers to make the reports more accessible. The technology exists to enable developers to create human friendly versions of their reports. Or at least give the ability to customers to create human friendly versions of the reports.l
Preflighting very well may be rocket science if your not "in the know". But that doesn't mean that we can't make it more friendly for those who are not.
If nothing else we need to actually consider the fact that we are in a manufacturing based industry. We make things from raw materials. Therefore we need to examine our raw materials and grade them against some sort of standard so that we can as best as possible control what comes in. Even if we can't control what comes in by sending it back and asking for something different we can at least know what we are dealing with as early in the process as possible. The more info we have the earlier the better we can make scheduling and production decisions. We can also alert our suppliers (customers too) that there are issues that need to be worked out and therefore schedules may need to be altered based on the results of the quality control process.
We are in an industry where margins may be razor thin for a number of different reasons. So we must be very careful about what we produce so that we waste as little materials and time as possible. It seems that far too many companies are happy to do something twice because it was inconvenient to spend a few minutes up front to check for issues because of a tight deadline (for example). Whereas if we spent a few minutes using technology to help get us meaningful information as quickly and early as possible maybe we would reduce the operating costs and spoilage. Who knows... Maybe we'll just "loose less money". Dare I say we might even be profitable?
Call it what ever you want. But in the end if nothing else it's a way to cover your ass in case shit happens.