Maybe the problem is how they visited Japan rather than Japan itself. Obviously if they joined a stupid tour as you described, whatever country they went to they must not have enjoyed it much.
Then there is less attraction for other East Asians to visit Japan than for Westerners, because everything that fascinates Westerners at first is how different Japan is. But after visiting South Korea, Singapore, etc. I realised that it is quite similar to Japan in many ways (food, temples, architecture, way of thinking...). It's a bit like for a Brit to go to Germany or France (or vice versa), but without the touristical attractions, as, to be honest, there aren't so many nice historical buildings left in Japan (or Korea, etc.).
Westerners come to Japan mostly for those reasons, which does not have the same effect on other Asians :
- different culture, buddhism, temples, kanji, etc.
- exotic food
- exotic people (i.e. who look and think very differently)
- J-girls (for men, and the Asian woman-Western man attraction is a proven factor)
- manga, video games, electronics, pop culture... (well, that could attract other Asians too)
That is why Westerners should be in general more interested in Japan than other East Asians.