People take things/issues/ideas in different ways. It is just their way of coping with what they fail to understand and in the long run helps them understand the subject better.
For example, in my U.S. History class last year, we watched a documentary about 9/11. When we watched as people jumped from the buildings, embracing death quickly instead of by fire, half the class responded emotionally and the other half laughed. They didn't laugh at the pain or suffering, but it was their way of understanding the situation and taking it in. Their laughing in no way reflected on them as people, it didn't lessen the problems, it just helped them understand the issues better.
Making a problematic and tough issue light/funny simply helps people understand it better and embrace the issue as truth. It also urges people to attempt to change the issues for the better, that is called satire..
Just because people take issues more lightly then you does not mean that they don't take it seriously, it's just a way of understanding the problems.
