Twitter has three options. You can tweet to the world without barriers and anyone can read and respond. This is great when you want to grow your network and have conversations. The second option is to send DMs to specific individuals or groups (if I remember correctly). The third option is to make your account private. The only people can read your tweets are the people who were following you when you made the account private.
The weakness of a private account is that twitter is a social medium and as such any time we @ or retweet someone they will be unable to see our answers. Any answer we write to those people will be unseen and so we will be tweeting in the wind.
My two reasons for keeping twitter private are:
A) More freedom. If we approve the people who can read what we write we can first warn them that we may be cheeky. We may something that we only think for long enough to write a tweet, and by the time it’s published we have already changed our mind.
B) The people we’re tweeting with are also private. If we answer a private tweet publicly then people may intuit what the conversation is about. We could use another IM platform but WhatsApp is part of Facebook and other IM networks have their own problems. People tend to be spread across platforms.
Twitter, Facebook and LinkedIn are three different types of social networks. LinkedIn is serious. I keep my profile up to date but not much more. Facebook is the network of former university friends. Due to this, I need to trust those I add. When twitter was a network of friends waiting to meet at tweetups everyone was accountable to the community so everyone had reason to behave a specific way. Now that trolls, hashtags and other issues are present keeping an account private keeps them away.
140+ characters is excellent to tell people how we feel but terrible for context. Blogging, forums and other long-form discussion websites are better suited to being public because you spend half an hour to an hour developing your idea, modifying it, and then sharing. That is long enough for an irrational tweet to become a rational post.
I’d rather have one to three blog posts by the end of a given day, than twenty-five to two hundred tweets. ;-). I haven’t tweeted like that in years for a reason.