I don’t know who would unironically enjoy racing at Tsukuba or the Tokyo Expressway courses. They’re fun to drive on and could be very fun for time attack, but they’re some of the worst courses for racing I’ve experienced. I’d argue the Nordschleife being in a similar category. (Edit: I’d also remove the solid walls from the Dragon Trail seaside chicane, and replace then with gravel traps.)
In all cases, they’re still very fun to drive and potentially do time attack, but there’s no run-off area and they’re too narrow for passing. And you just know that most gamers can’t race, so they’ll divebomb and try to pass at literally any corner, while giving no space at all, which is further exacerbated by the short length of the races, which gives drivers less chances overall per race to improve their position. These courses are among some that I’d bar from ranked races, though not ranked time trials. It’s not like you’d be unable to race on these courses in lobbies either, so I don’t think anything would be lost.
Honestly, I’d really rather have any hypothetical future iterations of the Roadster Endurance race (both in the campaign and online) back at Apricot Hill, rather than Tsukuba, which isn’t even really raced with cars in real life. It has time attacks with cars, and motorcycle racing, but not car racing, AFAIK.