liudr:
everyone else ended up providing the support for the lazy seller.
See, that's where I'd characterize it differently; I wouldn't necessarily call them lazy, just cheap. They specifically left out support, in a bid to lower prices.
As for everyone else providing support, I think that's where we all come in, if we see it as enough of an affront. There's a great little niche automotive tuning package that a couple of friends of mine created quite a few years ago. They built a community around the product (an "in-club" private forum for owners), provided absolutely fanatical levels of support to their customers, gave the source code to the client software away for free so the more technical folks could make changes if they needed them, and generally treated everyone well. They got popular enough that it became worth the effort for people to reproduce their piece of interface hardware that effectively served as a security dongle as well, and they started selling it on eBay and local forums.
The community responded by effectively driving off the forgeries. Requests for help with the software on other forums were often met with "why don't you post that question on the private forum?" When the inevitable "I don't have access to it" response came, people with the skill to help refused to assist until they had a legitimate copy. People trying to sell the knock-offs were shown the door on most of the related enthusiast forums, and folks would report "sightings" in craigslist ads and forum classifieds with what seemed like a little bit of glee for being able to help catch them.
(Their new version of the product is significantly more difficult to replicate; it was an eye-opening experience that they took to heart. ;))
Tolkien managed a similar feat early in his career, as a result of lacking copyright protections for his work here in the U.S.: his fans went to bat for him and refused to do business with the company that was perceived as ripping him off.
These are rather extreme examples, but the idea is the same: if they're having trouble with a product they purchased, why don't they ask the seller for help? If the seller is unresponsive, perhaps they should ask themselves why?
liudr:
With how much time I put in my Phi-1 shield design and software support and money I made, it's not very promising even as a casual designer, although I've not heard one complaint on my design yet. Hope my next step is paying off my time. Not trying to make money this time either.
Ponoko has some awesome advice for this situation. Actually, they have ten articles stuffed full of great advice on the topic, but there's one in particular that stands out for me in this situation:
Rule #1: Make a profit.
Makers sell things far too cheaply, fearing that they're ripping people off by charging what they personally perceive to be large markups. The reality is, that markup is what ensures you can keep making the product. Doing something because you love to do it and because you want to help people with the fruits of your labor is not at odds with doing so for a fair price.
liudr:
Will open source hardware worth your time designing? That becomes my question.
Again, see Teensy, or see my friends above (they didn't release their product as open hardware); both were replicated. If you're popular enough to buy, you'll be popular enough to copy, and replicating an existing board is the easy part.
This isn't an open hardware failure, it's a business model failure. Photographers saw the stock photography business dry up because of sites like Flickr and iStockPhoto; newspapers are having their lunch handed to them by blogs and TV news; software companies are realizing that boxed sales and upgrades don't mean a solid recurring revenue model anymore. Lowered barriers of entry for amateurs and ease of reproduction through improved technology have cut into dozens of business models, including the sale of hobby electronics.
How's that for pessimistic on a Sunday? It's not the end of the world, though; you can either feel badly for yourself or blame the people "doing this to you", or you can rethink how you do business (or even if what you're doing is a business at all, or if it's a hobby you'd rather enjoy for the love of doing it than commercialize, as Graynomad points out).
(Yikes, that was a lot longer than I had planned. My apologies for spamming everyone.)