FWIW, I think your analysis (young, educated, bourgeois) is spot on, and that bikeshare companies are completely aware. Check out this map of Citi Bike's availability:
If you're not familiar with NYC: it's only available in business, wealthly/middle-class, and rapidly gentrifying areas. To continue my baseless speculation: it wouldn't surprise me if Citi Bike's (hypothetical) profitability relied on only serving these populations. Reprehensible, and another reason to agitate for bike shares as an extension of public transport.
Not writing off! I'm in that demographic. But let's call a spade a spade.
That being said, I think there's a substantial difference between PCs/cellphones/digital photography and bikesharing: the former were also adopted as business interests, while the latter is just a luxury or employment perk. PCs and cellphones reshaped the office, digital cameras reshaped newstelling and photojournalism; I find it hard to believe that bikesharing-qua-private-service will be doing much reshaping.
Not as big as cellphones obviously. Still something.
People who travel to client sites in dense urban environments may have even more interesting numbers.