"Non-technical solo founders need to be extremely product focused. They're not purely business-y or marketing types"
Marketing gets short shrift in the tech world, probably because tech is one of the major industries in which the marketing function and the product development function are separated to a large degree. But true marketing, as a discipline, is very much product focused.
In fact, the discipline is often said to encompass "Four P's": product, price, place, and promotion. Many people -- not just in the tech world, to be fair -- tend to conflate the "promotion" function (advertising, communications, messaging) with marketing in general. In fact, promotion is just a subset of marketing. It's an important subset, but it's a subset nonetheless.
The best marketers are well grounded in, and can draw upon, the full-spectrum marketing skill set. Finding one of these marketers can actually be very valuable to your company. Having this full skill set can be very valuable to you, whether you're a technical or non-technical founder.
[A (hopefully) interesting side note: http://en.wikipedia.org/wiki/Marketing_mix]