Nikkei index reached its peak in 1990-1991 and never completely recovered. That seems to me a big example against index tracking ETF.
Are they still popular in Japan or that example made the point against ETF ?
The Japanese stock market offers a wide selection of popular ETFs tracking the various indices and sub-indices of the Tokyo Stock Exchange. See this page from the Japan Exchange Group site for a detailed listing of the ETFs being offered on the Tokyo exchange.
As you have suggested, one would expect that Japanese investors would be reluctant to track the local market indices because of the relatively poor performance of the Japanese markets over the last couple of decades. However, this does not appear to be the case. In fact, there seems to be a heavy bias towards Tokyo indices as measured by the NAV/Market Cap of listed ETFs. The main Tokyo indices - the broad TOPIX and the large cap Nikkei - dominate investor choice.
The big five ETFs tracking the Nikkei 225 have a total net asset value of 8.5Trillion Yen (72Billion USD), while the big four ETFs tracking the TOPIX have a total net asset value of 8.0Trillion Yen (68Billion USD). Compare this to the small net asset values of those Tokyo listed ETFs tracking the S&P500 or the EURO STOXX 50. For example, the largest S&P500 tracker is the Nikko Asset Management S&P500 ETF with net asset value of just 67Million USD and almost zero liquidity.
If I remember my stereotypes correctly, it is the Japanese housewife that controls the household budget and investment decisions, and the Japanese housewife is famously conservative and patriotic with their investment choices. Japanese government bonds have yielded next to nothing for as long as I can remember, yet they remain the first choice amongst housewives. The 1.3% yield on a Nikkei 225 ETF looks positively generous by comparison and so will carry some temptations.