Oddly enough, with as much time as I have spent in Japan, I've never run into that. In fact many of the Japanese I meet are embarrassed that I have a better understanding of something they consider fundamental to Japanese culture better than they do.
There is an excellent interview here with a great 20th century budo teacher who points out, quite correctly I think, that modern Japanese are nearly as culturally different from Sengoku and Edo Period Japanese as Westerners. So if cultural purity is required to understand budo, than no living person is qualified. I'm not arguing particular cultural experience is required. I am arguing that particular historical and philosophical knowledge is. That knowledge is available to anyone who puts forward a little effort and thought.
It was interesting - about the same time, the guy's father came home from work (he worked out of town and was only home intermittently). I got real polite and bowed and said I was honoured to meet him. He got his son (this in in 1977) to tell me that he was a modern Japanese and didn't do all that formal bowing stuff even though it was a samurai family. The kid... I showed a photo of him to some other friends in Tokyo... apparently he was part of an ultra-right wing, ultra traditional group, so.. perhaps his father was more 'modern' than the kid.
Not long after the father told me to back off trying to be "too Japanese" my friend told me the good news that, because I wasn't Japanese, I could never understand or be any good at budo (I was training in judo at the time).
WRT Kata - sometimes I have trouble seeing the point of kata...