I have two Twitter accounts: a pseudonymous one with a few hundred followers where I talk about my hobbies, and a professional one with a very low follower count where I talk about tech.
The first account is a lot of fun - I can post about something and 5-10 of my Twitter friends (people with shared interests who I only know via Twitter) will chat with me about it. The professional one is giving me the experience you're describing. A couple coworkers follow me and a few random people, but not enough of an audience for anyone to see my tweets. It feels like a waste of time.
I consider it a design flaw that Twitter makes it so hard to get your account off the ground. Sites like HN and Reddit allow you to jump in the conversation on a fresh account, but on Twitter you're just invisible. I got my first account up and running thanks to some real-life friends following me, and I can't imagine how to make my professional account stand out.