Again, I'm just trying to argue against nomenclature that's confusing issues here: I feel you're improperly advertising yourself when you call yourself a designer these days if you really do know the science of interaction design and can use its tools. A great majority of people who are designers do more beautification than usability. You need a different noun if you're truly doing real usability stuff, including the studies, heatmaps etc, that make up the UI Usability world's process.

>/UI/UX/Interaction design is a new thing

I'm going to disagree with you about this. It was a specialization in many schools by the end of the 90s in computer science departments (Called Human Computer Interaction). I have two very dear friends with degrees in it who are 29 and 32. Here is one such program: http://www.gradadmiss.gatech.edu/programs/multidisciplinary/... Actual industrial design degrees (which are pretty applicable to software) have been around for decades.

There is a big difference between "People who make things pretty" and "People who make things interact well with people" and the training is different. Now if a person trained in one of those worked on self training the other, it still seems like calling themselves something acknowledging the dual nature of what they do: Something like UX Engineer and Graphic Designer would be more exact than the term "UX Designer" which in practice usually seems to mean "Artist who makes things pretty then loudly, without good reasons, without a willingness to understand costs or decades of human/computer interaction, requires a large amount of authority acceded to him without further explanation and requires we do a lot of things just so without talking about tradeoffs because he doesn't seem to really have a mental model to talk about what he does so can't really compromise well and retailor his solutions to the issue".

Those using the title often feels like people trained to do good art (even good commercial art) refusing to do a job and explain themselves when how they want their art animated doesn't actually make for good user interactions or would cost 3 arms and 3 legs more than the client has.

A lot of this is a function of how people without true backgrounds and training in design get into the field: the computing field is super tolerant of people not trained in this stuff but who get stuff done. Happens with programming too. But programming is a little less tolerant of handwavy BS than art is (at a point, its a "did it work" thing which is somewhat demonstrable for programming). Where "Did it work" for design isn't really as testable without a user study. (I'm not saying non-trained by a college to do this thing shouldn't be in the field, just that they're less filtered).

Now, all of this isn't to mean: Designers shouldn't know the flow of what they're doing the art for. But until a designer show me a track record of UI improvement and comes equipped with the tools to show you made something better, lay off the misguided airs of certainty. Those tools exist. I feel if you can't use them, and can't prove yourself you got to let your client know this is most art than science and they should also really listen to other voices in the process.