When people use things like this I try to catch it. This isn't a reasoned argument. It's meant to have the reader or hearer feel a certain way to change minds.
Why do you interpret her reporting that the term is "old-fashioned" as an argument that it shouldn't be used? She's not making an argument, just remarking on the term.
Language is only useful if we all agree on a common meaning for it. If you use old fashioned language I may still recognize it, but it is still wrong: you need to update your language to whatever is current (this does change!) so that we continue to understand each other.
Maybe I can't define why it is old fashioned, but if it is old fashioned it is wrong. I would hope that people who better understand the details have a better definition of the terms in use and could apply it, but all I know is your usage is old fashioned. (Note, the above doesn't preclude the idea that I'm wrong and the language is current, merely that we both need to do more research and should be more careful in this area until/unless we do!)
> Language is only useful if we all agree on a common meaning for it.
Is it possible to agree on a common meaning for language using the language for which we are attempting to agree on the common meaning? On a logical level, I think I reject such an idea, although I would be fascinated in an argument that suggests such a thing would be possible.
> all agree
Information theory suggests that commonly used symbols should be short and rare symbols should be long. Any subgrouping of people will encounter scenarios requiring different ideas to be discussed at different frequencies. Jargon differing amongst people is to be expected and is what at least I have observed. I also reject 'all agree' on an information theory level.
> Language is only useful
And finally on a personal note. I generally misunderstand what most people are talking about most of the time. I think of it in terms of being weakly immune to peer pressure, but the other side of the coin is that I have a hard time keeping up with whatever group I'm a part of. And vice versa, I often say things that others quite obviously misunderstand.
However, I still find language useful. Even when there is no agreement on common meaning. Even when jargon necessarily forms differently between groups (and often even between individuals). Even when we try imperfectly to define language basing it upon itself. Using old fashioned language (or simply uncommonly agreed upon language) isn't 'still wrong' even if recognized. It is, I assert, the only way language can even be.
When people use things like this I try to catch it. This isn't a reasoned argument. It's meant to have the reader or hearer feel a certain way to change minds.