I highly doubt people will flame you for your assertions of a true RPG in the PNP sense and how they don't apply to the RPG video game genre since that's been accepted for as long as I can remember. And before I forget, commendations on your superb game examples; I can't think of any key RPGs missed.
Anyway, your definition of an RPG is based on the very origins of the word. However, by now, mainstream video gaming has accepted a different rough definition of an RPG with character growth as the pivotal aspect. Not to mention the actual words role-playing-game separated out implies nothing of the PNP sort, but I'll ignore that for now and accept the acronym "RPG" to refer to the PNP variety.
You're certainly not at fault for believing video RPGs are bastardizations of the original meaning, and yet does that ultimately serve a point when the new definition has now surpassed the old in far greater degrees of popularity? Is there a point when D&D computer/video games have attributed their names and "RPG" labels to games that are world apart from PNP RPGs?
It's unanimous that CRPGs strive for customization/choice while JRPGs focus on characters/setting. If not for the feeling of JRPGs (whichever feeling suits you best to whichever JRPG exudes that feeling best), is there any other reason? Gameplay? No chance? Story, visuals, music? Only to contribute to this feeling/atmosphere. On the other hand, CRPGs encourage decision making and micro-managing; players enjoy the free-spiritedness of the world. Gameplay? As long as it contributes to the realism? Everything else? The same.
So while CRPGs attempt to fake life in a different surrounding trying to impress you with its unique aspects of realism, JRPGs move you to an entirely unbelivable world in order to move your emotions.
CRPGs undeniably wish to stay true to the original PNP vision (albeit with the innovative DM replaced by well-thought-out events), both to provide you a world to make your own as you wish (an outgrowth of American concepts of liberty perhaps?). But JRPGs direct you to present you just the right atmosphere with the feeling they intend to create, glorified movies using the power of playability to lure you into taking a personal interest. So with further review, you can say the 2 types of games are even different in intent than you make them out to be.
With JRPGs, the developer fears openness; with each additional choice, the player is sucked more into creating their own vision of the game and missing the tone of the game that the developers intended, whether for better or worse. If you have a game of 100 side quests staring down at you, how can you hold attention to the main quest? Meanwhile, the sandbox CRPG lets you meander about as you wish and provides a feel-good story just so they aren't accused of laziness and you're able to feel you really mean something in the world (since who wants to play a 1-player game knowing they're peons in the world? Certainly not PNP players). Introduce too much plot and the freedom disappears. So is there even any common ground? I don't believe so at this point.
Herein lies also why JRPGs can't be played for many times before you gain a tolerance for the feeling that the RPG gives you. A CRPG's actions may bore you, but if it didn't, you can keep enjoying the power and freedom of having a persona in a "replica" world. What makes an MMO more special than a normal CRPG? First, you have interaction, and secondly, for far more likely reasons, the fame/power (I say "likely" because few play MMOs to role-play; some even pay others just to play and get levels/gold/items). The purpose of a PNP? Camaraderie, freedom, creativity, fame/power, maybe some other stuff I'm forgetting. Unless there's real role-playing where there's more than 1 role in the game (as you aptly put it: the "adventurer"), MMOs aren't any more true to the vision.
Anyway, I don't understand the part about JRPGs changing comparatively little to CRPGs. Sure, WRPGs have been able to offer ever-more freedom as technology increased (as their original vision intended), but for what reason do people play JRPGs? What sort of change can you measure if you don't know what the unit is? If JRPGs are truly a boring mockery, wouldn't people have stopped playing them by now? CRPGs simple don't have the tools by design to suck in the emotional JRPG players.
So ultimately, I agree with most all of your comments and little of the opinion. Tell me though, do you ever feel emotional inside playing certain games (story, characters, music, magical atmosphere)? Or is the experience predominantly mental (gameplay, freedom, customization)? Forgive me if I'm wrong but I sense the latter, and with that point of view (whether it's something that can be changed or not), I don't think you can fully enjoy JRPGs.
Finally, sorry for the repeated explanations and lengthiness. I certainly respect your point of view; no question it's well thought out and from a knowledgeable perspective. But it's sort of bizarre to claim that there's nothing worth playing in JRPGs (implicitly referring to everyone) when my sense of pleasure says otherwise. And if your whole plan is to simply refer to RPGs by some other name, predisposition towards precedence and lack of effect says otherwise. Best of luck to you, but remember that it was JP folks who ignored the implications when they claimed the term "RPG" and it's also them to whom you won't be able to convey your message to.