SNS in Japan and the US

I join face/book for SNS. My frIends in f/b are entirely in Japan and the US. I have noticed they use it in different ways.  The US people often appeal their belief in some religion or in some political party while japanese scarcely do that way but post on something interesting or amusing around himself/herself, that is, if I could say in this way, something trivial. Of course, there are many exceptional cases in both countries.

What has made this difference? So far, it seems to be because of the heterogeity of the society or the preference for the homogeity in the society. The US is often told as a melting pot of races. The heterogeneity is a prerequisite for life. In such a society, it is recommended to appeal own idea or belief. On the other hand, Japan is believed to have been a homogenous society as for the race. Of course, there has been an argument against such a simplification. There have been a variety of minorities in the society, who are believed to be suppressed even at present. As a historical tradition, however, our society has regarded the homogenousness as a virtue. We have aimed and behaved to share somethig together but not to express own opinion different from others.  This seems to be the reason for the difference.

I don't know which is right or appropriate. Both might have their reason. I feel that our society is now getting more freedom in expressing own opinion even though it is not so obvious  as in the US is not recommended at all. I don't know if it is the right way to go or not. At least, we need to be trained to discuss openly here in Japan. Expressing own opinion different from the majority often is inclined to be taken as insanity or, at least, being out of the "atmosphere". The open mindedness to the minority seems quie insufficient. Maybe, it will be changed little by little. On the other hand, so far as I read in f/b, the appeal of own idea or of belief in the US is often too direct or too conclusive to accept the existence of the other ideas or beliefs. It doesn't seem to allow any further discussion. Especially, religious matter sometimes makes me sick.

SNS such as f/b is not suitable for a tool for thorough discussion. It seems to be the case that we scarcely could make any detailed discussion in any internet media like f/b or twitter etc. There seems to be rasion detre for such as blog or even conversational CW on the radio. Me? Of course, conversational CW comes first. But f/b as well from time to time. Couldn't it be the first step for further discussion? Does it still remain an inner circle especially in Japan?