I work in network infrastructure/security design and there I actually DO perform miracles (of an IT nature..hehe) by setting up/connecting networks (physical and virtual) in ways that make some people's head spin! 
Thing is, I don't come cheap. That is my single best defense against irrational/demanding users. You want me to make the sun shine? Hand over the keys to that beach-house! 
But see this is where it becomes obvious that we're dealing with many seperate issues.
1. Most people in IT do in fact look down their noses at end-users (sometimes this is hard NOT to do). It's the classic "god-complex" that other professions (ie Doctors etc.) struggle with as well.
2. Most end-users look at buying and using a PC as no different than buying/using a new microwave. It is an electrical appliance is it not? That's a problem because obviously (unless you're nuts) you don't "modify" your microwave but the second you actually begin using your PC you are in fact constantly modifying it making after-sale support of that PC a difficult and time-consuming endeavor.
3. ISP's have (in many cases) bitten off more than they can/should chew by providing security-software suites and router-configuration etc. etc. (often due to competing with other ISP's for customers). Once they opened the door on providing anything else but the "connection-service" all of these other issues created by unknown/uncontrollable variables became a problem dumped squarely in the laps of often under-paid/under-appreciated/under-trained support staff who then get frustrated at having to deal with non-ISP related issues while being expected to keep the call-queue moving.
4. To top it all off, there are little or no STANDARDS in the PC (home/end-user arena) AND the PC is the epitome of ultimate CUSTOMIZATION. Anything goes for Joe-user and that more than anything makes "support" demands of users damn near impossible to fulfill on any appreciable level. Every IT-guy worth his salt knows that cleaning out a virus-infected system is NOT actually returning the user's system to it's original state. System files have been more than likely damaged by the infection and eventhough the infected files are now cleaned/removed the "damage" often remains. So some of us will explain this to an end-user in terms of getting into an accident with their vehicle and having it repaired. The vehicle will never be the same. Fortunately in the PC-world we can actually revert back to the factory model (re-format) but how often is this process (or the need for this process) properly explained to an end-user?
End-users often have seemingly irrational demands of IT professionals because they don't actually understand what it is they're even asking for. So who should be tasked with educating the joe-user? The ISP support tech who just wants the constant "above and beyond" demands to stop? The comp-shop tech who doesn't understand the end-user's needs because the end-user lacks even the initial comprehension to explain their needs correctly?
Here's my (somewhat tongue-in-cheek) suggestion:
I think the answer is more intelligent SOFTWARE and point-of-sale STANDARDS. OS's need to come with "classes". When you install an OS in the future the FIRST thing it does is ask "Beginner", "Intermediate", "Advanced" user? Then depending on how you answered that question your OS will allow/deny you certain customization of itself while explaining it's functionality so that an end-user must finally ACCEPT responsibility of the state of their hardware/software. That is the biggest hurdle/gap (as I see it) for the industry and the user to bridge. The user needs to (knowingly) accept responsibility for the state of their PC and that can only happen when they actually understand their software/pc.
End-users must recognize that a PC (and all of the software on it) is like an open-world in which and through which almost anything can be achieved. That means exactly that...... "almost anything can be achieved"....meaning that on any givien day things could go well........or things could end in disaster. If the end-user is refusing to educate themselves......then FORCE it on them at the point-of-sale. Make STANDARDS at the point-of-sale. What kind of user are you? Beginner, Intermediate, Advanced? Each level comes with more/less after-sale support.
the Monk