Differet attitudes in Criticizing the government between America and Japan: Part2

In the last blog post, I pointed out that Japanese media makes less parody on politicians than American media does, based on the observation of television shows in the two countries. I also noted that while this is the case, Japanese people do criticize the government or politicians just like American people, if not as intensely.
Surely, there are parodies and cartoons found on the media, but there are definitely less compared to America. For example, if I go to google.com and search for pictures with “Obama cartoon,” 24 out of 1st 30 results are President Obama’s cartoon. However, if I go to google.co.jp and search for “菅直人　漫画,” which means “Naoto Kan cartoon,” only 10 out of 1st 30 results is the actual cartoon of Prime Minister Naoto Kan. This huge difference in number shows how American media makes more cartoons of politicians.
Probably the only logical explanation that can be given for these difference is that the Japanese people do criticize the government or politicians, but not necessarily by using cartoons or parodies. What’s the possible reason for this?
First reason is that Japanese people want to separate and distinguish serious topic and funny theme. Serious themes such as politics are often discouraged to be brought up in a funny conversations. For example on TV, the serious topics are only discussed in news programs, while funny topics are only on entertainment programs. People do not mix serious and funny matter in the same discourse.
This separation is probably due to a particular aspect of Japanese culture, which is the sacred-profane dichotomy(Hare and Ke). From the past, Japanese people have considered it important to clearly separate special occasions and daily life. This separation must have prevented Japanese people from having the news parody like the Daily Show and Colbert Report.
I wonder if there would be Japanese Daily Show 50 years from now.