There is one highly essential element missing in the descriptions above.
It's 'business value'.
People outside of our field usually DO NOT CARE if something is easy to use or not. They are not paid because what they do is easy to use or 'human'. That's a hygiene factor to them. Or it is something that they ignore because they don't (yet) understand it.
We need to remember that generally speaking the reason we are able to do this profession is because we are trying to create a better experience for users which in turn generates either a. more money for the organisation, or
b. less cost.
Simple as that. There are other benefits but they pale into insignificance compared to those two (in a commercial environment at least).
Our job is to bring the process of how we create this value, and why, to life for people so that they can understand and start getting to grips with it.
My fave example is (of course) the tale of Apple & the iPod. How could a company down on it's luck in 2000/2001 - about to go out of business some thought - bring to market a product that was
a. more expensive than competitors
b. not as good sound quality
c. less storage capacity
and have the audacity to go on to absolutely clear up in an established industry, to the extent that I think ITMS is the #1 retailer of music in the US, and getting to be that way in the UK too.
The answer is - the user experience! If you look at Apple's share price over the past 10 years you can see how this has added value.
For more detail on this see: