Limor Fried's business is successful for what she has done. Not only are her "pre-engineered solutions" good for artists and other maker types who don't know much about electrical engineering, they are useful even for engineers willing to trade money for time by purchasing pre-engineered modules to get a particular job done.
In addition to her pre-engineered modules, she does a good job of procuring and stocking useful purchased items.
Her appearance may appeal to some, it may be neutral to many, and discourage some, but I'd say any influence on her business is down in the noise. She's very successful because she has so well met the needs of a significant group of people. Her appearance has nothing to do with that.