While that's certainly true, I'd hesitate against thinking you know a lot about the market even if you consider yourself part of it. Your market might be a lot more fragmented and diverse then you think -- it's still worth assuming that you'll have to learn everything about it.
About 20 or so, but their responses have been much more scattered. It's harder for them to pinpoint their problems, so we've decided to shift focus to doctors for the time being.
I think all of these points are valid, but I'd like to add another: being technical substantially increases your credibility among potential employees, VCs, and fellow entrepreneurs. Even if you're not planning to be the back-end systems guy or the rock-star designer once your company scales (and chances are, if you're a founder, you won't be), having coding competency helps you make those hires more easily and will win the respect of your more technical employees. VCs also love it when you're the one who has built the first few prototypes of your site and haven't simply outsourced the work to others.