Virtlink has a good answer.
I agree with him on the point that currently no one reads instruction manuals, but I would argue that in the past, people would read them since:
- They were so afraid to ruin something, that they wanted to ensure they were fully trained before operating the system;
- Systems were not design taking users into considerations;
- Users were not experienced at using interactive systems (computers, ATMs, phones...)
But things are currently changing since:
- Lots of users were born when computers, ATMs, phones were ubiquitous
- This generation is not afraid to try and error (most applications nowadays make it safe to fail since you can go back to the previous state.)
What I see is that there is also a new generation of system designers that realize this and is not afraid to push the system to the customers early. This means that after the product is in the customer's hand, it will be constantly changing and users will have to be constantly adapting to them.
A few examples of this are pretty much all cloud apps (gmail, google docs, facebooks, ...), some desktop applications that auto update like chrome.
Things are changing at such a fast pace that even your phone can change drastically (upgrading one android version to another, or upgrading iOS6 to iOS7).
And stuff that didn't use to change at all after you bought it like a car, nowadays can change at any time (Tesla can update the suspension of your car just like chrome can change its shortcut keys).
Designers are iterating quickly, and trying to figure out patterns for things that don't have patterns yet.
The hamburger icon is an example of this. Designers were using lots of different icons to mean 'settings' or 'configurations' - gears, wrenches, and all other kinds of icons.
At a given time someone started using the hamburger icon, and other designers though it was good (or simply though that it was being used by applications that have lots of users) and also started using.
So, Yes, designers seem to have lost some touch with users. Every time I look at the hamburger icon I still cant figure out why an hamburger would mean 'settings'.
But also, there are lots of applications and designers are trying to figure out new interaction patterns. So you need lots of iterations and lots of segmentation before designers agree on a given pattern.