It's no surprise that there was a *seeming* lack of interest... I'm a highly active Google user, I hang out on Open Source & tech sites, I usually check the Labs area every 6 months or so -- yet about a year ago was the first I'd ever heard of Google Health! I've never seen any link from the main list of tools or iGoogle or Chrome apps, and actually getting to GH was enough of a pain that I eventually set up a separate bookmark to do so.
There is a HUGE community of disabled adults & caregivers (of disabled kids or parents) -- 1 in ~6 Americans alone -- that would have been using Google Health if you'd actually bothered to do even a tiny amount of outreach, and usage would have grown from there as we enthusiastically told our aging Baby Boomer relatives/friends all about it. That includes our older Baby Boomer relatives, who now are keeping an eye on ailing parents and/or a disabled adult child. Boomers get attached to products long-term, tend to not install things like Ad-Block Plus (if only out of loyalty), and are used to paying for services -- neglecting them as a market is a profoundly bad idea.
Sad thing is, I remember a day when Google *really* did their work in making users aware of a new product, so that we'd learn about it through Slate, Slashdot, TechCrunch, Salon, etc. interviews & articles by tech writers given sneak previews or allowed interviews. Once we all had access, we then saw incremental improvements as we turned in suggestions or requests... It made folks happy to work with Google even as we became a bit wary of your power.
Instead what I see now is that you've dedicated time & energy setting up a new "look" for your pages, ignoring the riot of protests from users now on the verge of leaving. Watching one service after another be closed with only a half-hearted effort to gather users while you try to be "successful" by rebranding & color changes, and seeing search quality go down the tubes in the meantime I feel the same. Those are signs of a company that's privately in distress, and thus not one to trust with one's personal data, simply put.
Disneyland said something long ago that you should heed: every individual that takes the time to contact a company represents 1,000 individuals that felt the same but kept quiet. We're only a few thousand here based on this discussion, but that's just those of us that found out right away by visiting Google Health itself -- and it'd be a whole lot more if you'd bothered to rope in more users to begin with.
I read just a bit ago that Google Health -- which I had just started using to keep track of my mother's medications -- is being shut down due to seeming lack of interest...which is nonsense. So, I commented in their moderated Google Health Discussion post about the closing: