On top of that, how would you teach someone who doesn't give a shit about video games that much? To someone who only plays a couple hours of CoD a month and only buys 1 or 2 games a year, what lesson would they care enough to learn? That's the problem.
You'd be surprised. While many people do do this, tedium or boredom sets in at some point.
As far as the how, I have no set of proper guideline, I just show them what I know and what I've learned. If they are interested so be it, if not no worries. I will always be truthful with them though. I won't talk down to them, the gentle. Though should they be dicks about it, I will come off as harsh depending on the circumstances.
I remember encountering these two guys at a Gamestop. They were other customers they were literally just getting the next console for a new Madden, even though they couldn't get an Xbox series X yet. And the next sports game they're getting was going to be on X1 anyway. I literally told him you do realize it and playing the same game for years now it barely any changes or just a roster update. Both seem to acknowledge this, but they had to look of barely admitting it. It says even they were going through the motions at this point. I think the other guy had some interest in other stuff, but they mostly cared about sports titles. I mentioned all the other crap EA and 2K were doing. They were shocked but not that surprised the same time. All I told him was this "You both have a choice. What you do is up to you. Don't come crying to me when you get screwed over though. Best of luck and enjoy your new console if you ever get it." Their reaction was the equivalent of they're still getting it, but there are some uncertainty from them. Another way of teaching to the young ones is if you got actual kids yourself, or cousins, nephews, or nieces that are younger than you. As we seen from some of our members here, they've already gotten started.
