Having something to say takes practice. This is just my opinion. I hear this about not blogging often. I think even my pointless rambling have to affect someone somewhere... maybe even if it is only me. Expression... even shallow expression... is very important. I am not saying that the whole world should be keeping a weblog. There are other ways of expression. Example: See IP with his guitar down below? That guitar is his 'voice'... and from what I saw, it is a powerful one.
I think people need to have more commitment to and confidence in their expression... whether it be a journal, painting, or play a guitar. Having something to say just takes practice.
And maybe you look, sound, or feel like a bumbling idiot most the time... that is just going to get in the way of someone's (maybe your) moment of beauty and understanding... it is not about impressing anyone. I am an artist at heart, so I have a slanted point of view about the need/power of expression.