The tendency among Japanese people I've observed, both in the USA and in Japan, seems to be to use it more sparingly than most westerners seem to, and often to not use it at all. Same with soy sauce, for that matter.

But it seems to be highly subject to personal taste: I've seen Japanese people (in Japan) douse sushi in so much wasabi as to render the fish undetectable, and I've seen a high-end sushi chef completely remove the little plate of wasabi from the sushi bar when he discovered that his customer was Japanese.