I think the issue you're finding is that, people no longer want "normal" and "traditional" themes (thank God). The trick is to build them something they didn't know they wanted.

I tested this theory by producing an extremely niche theme. I then followed with very basic, traditional theme. The traditional theme, has yet to sale. 0 copies. Meanwhile, the niche theme? $2500 in its first month of sales. Over 40 copies in 30 days. And this isn't on Themforest or site similar to it. And, I'm not widely "known" in this space like some of the other developers are, so I don't necessarily have any more of an advantage that you do.

People are hungry for something different, and the future of WordPress themes lie in niche builds, and in themes that don't look traditional. My advice is to take a risk, and build something more than just a white site with a big image on top and boxes at the bottom.