The D&D spirit influenced both "Final Fantasy" and "Dragon Quest", two of the biggest selling games of 80s in Japan... which eventually grew into big games in the US as well. Tower of Druaga series also was D&D based IIRC. Legend of Zelda is very D&D-esque as well, Hyrulians are basically Tolken elves (magically inclined, pointy ears, "beautiful") while Kokiri are elves classic (magically inclined, short forest dwellers who help Santa build toys). Redead are your classic Zombies, and Wizards and magic items are the norm.
Its much like how the origin of "big eye anime characters" are actually traced to Mickey Mouse as the root of "big eye cartoon characters". There's a lot of influence from US to Japan, and vice versa (Lol Power Rangers)
The "strange" part is how language barriers seem to emphasize different parts. Like slimes in Dragon Quest are a major thing, but oozes / slime monsters have lost cultural significance in western D&D spin-offs like Diablo or Skyrim.
But go back to Bestiary 1.0 of D&D, and you'll see the significance in both Western and Japanese RPGs. Its just the different parts that the two cultures remembered about the book I guess.
Funny you mention Wizardry because it's yet another example of galapagos syndrome in action. They took the basic ideas from the first Wizardry (even the spell naming schemes are still used to this day in games series like the Shin Megami Tensei) and then.. literally stopped looking at anything new in the series. It's like Wizardry 8 never happened in Japan. Their Wizardry clones to this day still play like Proving Grounds of the Mad Overlord, the first game of the series, just with "improved" (but anime-style) graphics. The innovations like the more open world, various interactions with world elements, improved positioning and movement to the turn based combat and so on. There's still no concept of movement and position (beyond being "frontline" and "backline" binaries) in games like Etrian Odyssey. And then games like Fallout came out and showed it was possible to integrate a large amount of variable interactions with the world and consequences to your choices and Japan was still making those Wizardry 1 clones as if the genre could never, ever improve on that basic game design.
It's only very recently in Japan, with the success of games like Skyrim outselling their own jrpg in their home country, that japanese developers started to take note that maybe, the genre could do better than replicate the same game from the 80s ad infinitum. Which is how they ended up with games like FF15 which finally dropped the primitive, limited combat system from early wizardries that weren't even position aware. I prefer turn based RPGs, but I would take the real time FF15 over a system that doesn't even simulate the space in which you fight ignoring all potential positioning and movement tactics. Something that even board based, pen&paper RPGs can simulate. Their own take on the ability to feature combat in an actual environment usually precludes any RPG features other than pure combat, like Fire Emblem. They have good turn based combat but that's all there is to the game. No dungeons, no exploration, no world, not much choices, no nothing, just a series of combat missions after combat missions. It's the kind of hyperspecialization and narrowmindedness that led to the galakei and the inability to build anything like the modern smartphone.
Nintendo is another manifestation of the galapagos that has just recently started to panic and understand that they won't be able to go on forever like that. The next Zelda will finally let go of the template created by Ocarina of Time and will play more open. That's a start, considering how much they love to remake the same thing again and again. http://digg.com/video/zelda-is-going-open-world-and-the-game...
I see this trend in MMORPGs as well, where they try to "action" up combat and you end up running around avoiding circles on the ground while plinking away with your backing attack because anything else is suicide.
And i would love to see some flip phones in western markets. All i see now is a slab of glass monoculture. Cover up the logo and you would not be able to tell who made the damn slab.
At least compact cars have the aerodynamics excuse to all look the same. But i don't see that applying to mobile phones.
Google up the influence of Wizardry on JRPGs as just one well-documented counter-example. Japanese game designers in the 80s and 90s were designing in the 80s and 90s, not during the Tokugawa shogunate.