You hit the underlying problem right on the head there — being defined by a title is the main problem.
I’ve done most of my professional work on WordPress, so I could label myself as a WordPress developer. But then I’d be lumped in with everything (positive and negative) associated with that title. And WordPress is just the tip of my abilities, I’ve built projects in Ruby, Node, and Python, and have plenty of work in design as well. What title says all that? I guess I’ll have to update my resume to lead with “WordPress developer that also knows Node, Ruby, Python, and can design good too.” Well, maybe not.