score:8
I'll answer with a parable:
Imagine there's a $5 burger joint called Bob's Burgers in L.A. that's run by an old guy who's really passionate about burgers and has been cooking them for 40 years. And they're pretty well known locally among burger cognoscenti, but not a household name.
Then imagine there's a documentary made about the guy's burger obsession that goes viral in China. Suddenly it's a must-do for any Chinese visitors in LA, and there are tour buses full of Chinese tourists crowding the restaurant, and they yank the prices up to $50 and start requiring reservations in advance, and they're rude if somebody tries to book in Chinese or starts requesting their burgers without ketchup or Bob's homemade pickles.
Now the burgers are still the same, they just cost a lot more and are really hard to get. Can you see why locals would grumble and suggest that actually Fred's Burgers around the corner is just as good and charges just $10? Or why some visitors who manage to get a booking and pay $50 expecting the heavens to open and an angelic choir to sing when they eat it would be disappointed that it's actually just a burger?
This is pretty much what happened with Sukiyabashi Jiro.
Updating to answer updated question: Many top-tier restaurants in Japan are hesitant to deal with foreigners who don't speak Japanese, or are simply not equipped with English speakers to take reservations over the phone or explain everything when dining, so they require Japanese intermediaries or that you bring along a Japanese speaker. However, there are few if any places in Japan that are as famous among foreigners as Jiro and need to impose an actual quota system.
It's also worth noting that there are some top-tier restaurants in Japan that refuse new reservations from anybody, Japanese or not, unless introduced by an existing regular. There are a lot less of these than there used to be in the Bubble years though thanks to 20 years and counting of recession.