A blog professionally designed is quite comparable to a sophisticated looking business woman. Nice, but it causes us no emotions, no authenticity, it is a standard. Point.
The difference between professionally designed sites or blogs and the ones with a more unpolished look, is the difference between the standard sophistication and just good grooming that lets your personality shine through and allows individuality.
Of course I am hopping to upgrade some of my blogs, when the right time comes, but hope to achieve a more naturally groomed looking blog than a professional one, full of ads that go right in your face.
No, I want my blogs to be deliciously groomed and polished, feminine and delectable :). I am a woman and very happy with that.