While I think you make some very valid points here, I don't believe that

How can someone smile when they have seen the mess, pain and suffering of this world? They are either blind to it or, sadists.

I think that's narrowing it down a little too much...I think one should be able to smile, even knowing the horrors of the world, because despite all those horrors, there are rays of light and there is also beauty.

I really love the ending of your post <3