If there's one thing Twitter is not good at, it's holding a discussion on something controversial. Sean Coates noted this problem when he said: "I’m not worried about having my opinion disagreed with; I *am* concerned that I will be crucified for something I don’t mean." I suspect this is because you don't have the space to develop an idea on Twitter. It also doesn't help that Twitter is a conversation which means that people are arguing before you've written your second tweet!
As Chris Shiflett wrote earlier this month, real writing happens on blogs. With a blog you have the space to write down what you mean and develop the idea. However, even here there is risk. Lorna Mitchell noted that comments make it easy to criticise. You can leave an quick "drive-by" insult anonymously for minimal effort. This can become a disincentive to write opinion pieces on blogs too.
Like Chris, I also strongly believe in owning my data. My blog provides information that I want to share and more important, information that I want to find again! I was caught out on my Automatic Apache vhosts post where I linked to an alternative solution which has subsequently been taken down. Information that I want to refer to again must be on my blog as otherwise I can't be sure it'll be there when I need it.
I will continue to share technical things on this site as I believe that my posts are useful to others. Over time, I intend to blog more opinionated pieces. My views on some topics should be shared and would be a useful reference to point people at. Sometimes, I will turn off comments and encourage others to respond by writing their on their own blog. In more than 140 characters and less anonymously.