"niche" is simply shorthand for "niche market" IMO [1]. So it very much is a market and not a demographic. Without delving into a battle of semantics, I don't think either of these posts referred to a demographic of "people who are employed as dog walkers" ... I read them as the niche market of "people who own dog walking businesses."
I cannot answer all those questions about dog walking business owners because I am not one nor do I have insider knowledge about that business.
>> Do they care about being better dog walkers, saving time or money?
I'll go out on a limb here and say "YES", if you own a dog walking business, you care about saving time or money (or making more money).
That being said, I can answer all those questions about other niches (photographers, hackers, restaurant owners, churches, etc.) because I either am one or know that market. So, that gives me a pretty good starting point for identifying needs, doing deeper research, and then creating a product that meets those needs and that niche market is willing to pay for.
That is, in my opinion, what both posts were saying (in different ways).
I cannot answer all those questions about dog walking business owners because I am not one nor do I have insider knowledge about that business.
>> Do they care about being better dog walkers, saving time or money?
I'll go out on a limb here and say "YES", if you own a dog walking business, you care about saving time or money (or making more money).
That being said, I can answer all those questions about other niches (photographers, hackers, restaurant owners, churches, etc.) because I either am one or know that market. So, that gives me a pretty good starting point for identifying needs, doing deeper research, and then creating a product that meets those needs and that niche market is willing to pay for.
That is, in my opinion, what both posts were saying (in different ways).
[1] http://en.wikipedia.org/wiki/Niche_market