@innerdude
Interesting OP! Giving it some thought, I think a possible way to handle the situation would be in game in some way. Does the player’s character have any social connections? Anything along those lines you could use to maybe get your point across?
If he’s very mercenary in his approach, give him something else to care for. It worked for Han Solo, it worked for the Mandolorian. Figure out a Baby Yoda for him. Put the Baby Yoda at odds with his quest for more stuff… see what he decides the character does. See how that affects him and the other characters.
Help him find things in the game about which he can care. It’s hard to make a suggestion more specific without more details, and I’m sure you’ve thought of this, but beyond having the discussion you had with him, it’s what seems the next step to me.
It's only efficient if it's understandable.
It’s all understandable. Sometimes, it just takes a little effort. Usually, just asking the person what they mean.
This idea that jargon is this impenetrable obstacle is just tiresome. It’s a discussion board… exchanging ideas is what it’s for.
If you don’t like jargon… or more specifically as it seems from the many anti-jargon complaints, jargon not derived from D&D and its wargaming influences… you can just ignore it.
Alternatively, if someone uses a bit of jargon with which you’re unfamiliar, you can ask them what they mean. Most of the time from what I’ve seen here, they’ll happily tell you.
Contrary to many complaints, the use of jargon is not an attempt to shut down discussion, but an attempt to make sure folks are all on the same page. It’s done to clarify and enhance discussion.
I've improved my RPGing quite a bit over the past 20 years. Other people, including posters on these boards, tell me that they have improved their RPGing too, and some of that has been as a result of discussions in which I have participated.
@innerdude is one of those people - see, eg, this post:
Why Jargon is Bad, and Some Modern Resources for RPG Theory
I don't know why you want to stop these conversations.
Add me to that list! My gaming has benefitted greatly from my time here, and through people sharing their ideas and those of others. I’ve learned a lot, by folks explaining things to me, but also just by being forced to really examine my games and methods.
Having a vocabulary for a lot of these things has really helped. I’m not even a heavy user of jargon myself, but that doesn’t matter… it doesn't change that it’s helped me a great deal.