Educating them is fine as long as the customer has the time and/or interest. They hire you and want you to wave that magic wand and make everything alright and perfect for them without having to get involved too much. That is your job in their eyes and it is right to think that. And yes, they are ignorant often and underestimate what things will cost in time and money, but again, it is so in all service oriented jobs.
Add to that the horrible and mediocre taste level, the low percentage of income most sites will generate as opposed to a physical presents for those clients, it is hard to convince them to pay more than they have budgeted based on their perception. Combine all those points and you end up where you are today in this industry. I do not see a change anytime soon, there are too many parallels in other industries to point to the same mentality.
Look at architecture as an example. The horror that is committed with cookie cutter places and shoddy workmanship. It can all be done better and people are mostly aware of it, but they could not afford to buy a place that would cost five times as much, but they have been sold and bought the illusion that the place would be almost as good as the real one. So it is with websites. People who get stung by unprofessional "professionals" have just bought their own unrealistic dream. And so it is and will be, that is how most humans live in all their endeavors.