Another thing to keep in mind: Even with a great deal, some people don't want to spend the money or can't spend the money to take advantage.
For example, one could fly from Australia to Europe in J for about $3k or so return (rough numbers, just work with me here). Even with no reward points, most would agree that $3k is excellent value; you could barely find a J return in cash for that price or close (let's not consider the nesting tricks for now; most wouldn't travel that regularly to take advantage).
However, it is $3k. You can pick up a return Y fare for half that price, even less. Someone needs to "get used" to paying that much for a fare which they know is a good deal but still is more money than they would otherwise spend. Yes, you can sell the comfort, the lounges, the experience (and some may not have any personal experience or at best your recounted experience to go by), but money is money and let's not kid ourselves in thinking that $1500 or so is nothing as far as a price difference goes - that's still a decent amount of money to many people.
If it were simply an argument of flying J at Y prices (a hark back to the days with less enhancements and a parity USD), or for a fraction more (e.g. within $500 or so), there would be no contest, of course. (But you'll probably end up doing all the leg work finding the seats! Which leads to another reality: plan your holiday around the seat availability, not the other way around!)
As for earning points and so on to use towards flights (e.g. through credit card spend, or even travel if the person travels enough by air), that's a different thing.