Whose interest did those things capture initially outside of a small group of technical people? Were they built and people just lined up outside of Walmart to buy them?
Example:
> Who was the market for the original telephone/telegraph
Gee ... um ... I don't know. Everybody in the world who thought it would be more convenient to get instant verbal communication over a letter that took weeks or months to deliver/respond to?
Let me put it another way. Pierre Omidyar is a technical guy, and more specifically a programmer. Did he choose to develop something that solved an obscure technical challenge, the goal of which was to be published in some computer science journal with a subscription base of 12 people?
No. He had a rare abililty of having both the technical talent and being able to think from the perspective of the general population.
Hence someone like him would be an exception to what I said I've observed.
But for everyone like him that can be cited, I can introduce you to 20 programmers that are trying to start startups around "challenges" so specialized and irrelevant-in-the-scheme-of-things that I know for sure they did zero market research before starting or even during.
Sure, lots of things that seemed like a waste turned out to be very useful with the benefit of an unexpected consequence coupled with unpredictable developments and the benefit of hindsight.
In general, though, I'd prefer to start with "what's needed" and try to come up with a technical solution as simple as possible rather than "what's the coolest thing I could work on technically" and then spend time on that only to find out that 5 people in the world would actually buy it.