seems to me like taking the philosophy that if all the other lemmings are jumping off the cliff then it has to be okay....
You're equating using the phrase "upwind leg" with jumping off a bridge. This can't be any further from the truth, especially considering you're almost 100% more likely to be understood using that term to begin with.
1. just because it is a common phrase which is often incorrectly used with regard to position does not make it right.
Yes it does. The whole point of the phrase is to convey where you are. If you say "Cessna 1234 is climbing upwind" you'll be understood by everyone listening.
2. the easy road and the right road are often not the same.
In this case, what exactly is it about the "hard road" that makes it the right road? Are there any inherent safety benefits to using the term "departure leg" as opposed to "upwind leg"? Do you think that one extra syllable somehow makes the call more distinguishable? I'm not being sarcastic, I honestly want to know why you think "departure leg" is better other than just "uh it's in the AIM"
If the FAA were to change the name of that leg to "upwind" would you protest that? Or would you gladly switch over?
3. isn't it our duty as instructors to be precise in teaching the correct phraseology?
Yes. But what am I going to say to my student when they ask me why the Jepp book lists the "departure leg" as the "upwind leg"? Or how am I supposed to explain to him why every other single pilot is saying "upwind" instead? Its a uphill batter that will never be won.
4. the FAA does want us using the same phraseology, which is why there is a printed AIM. It is unfortunate that a.) students are taught the wrong phraseology from instructors that do not know any better and b.)instructors lower their teaching standard to accept incorrect phraseology because it is "easier" and not necessarily correct.
I never even heard of this whole "departure" nonsense until about a month and a half ago. I had absolutly no idea. I've never been to an airport where saying "upwind" would cause confusion. How exactly was I taught wrong? How did my instructors lead me astray when I have never and WILL never run into a problem saying "upwind"?
If a student says today's pressure altitude is xxxx and is talking about density altitude, do you correct them? Why? Because it is the incorrect term to use and they have incredibly different meanings.
There is no difference between that example and correcting a pilot to call the departure leg the departure leg and upwind upwind; the only difference is an instructor's attitude to choose to not correct something which is wrong.
If every single pilot out there regarded what the book refers to as "density altitude" to be "pressure altitude", then I wouldn't correct him. Why teach your student a phraseology that absolutly no one follows?
In your example, the terms "density altitude" and "pressure altitude" have no confusion regarding what they refer to. I would correct the student.