As much as I dislike linking to a Ted Talk, I believe this talk hits on a variety of these types of errors:

http://lalone.us/npUoTH

The early history of radio is a good example - there was a vibrant two-way amateur culture of radio hobbyists that resembled the early-WWW in a lot of ways. But government regulations favoring commercial one-way broadcasting completely changed the model of the medium, despite the argument that two-way radio might have been a "better" use of the technology (or at least a desirable parallel option).

A few ideas:

A lot of early film theory (of various kinds) might be considered a reaction to what they perceived as a gigantic missed opportunity in using film as "merely" a way of recording scenes for later playback.

For specific works, adaptations are a common place such accusations come up, where "bad" adaptations are accused of being half-assed transcriptions that fail to take the target medium seriously.

There's probably something relevant to be found in the many critiques of virtual-reality research.

How about television broadcasting? it's development could have been similar to early radio or early Internet, but was largely made inaccessible to the average person (and still is) because advertisers misused the medium.

Imagine a world where any joe blow can claim some spectrum and put their own content on it. Youtube would not have been such a novel concept and copyright policy might not be so oppressive today, had the world experienced freedom in broadcast television in the decades before the Internet.

The Software-as-a-Service (cloud computing) trend is also a very unappealing way to use the "medium" of the Internet, because users lose control of their data or software, and a happy medium where users are granted full control of their data while it remains stored on a remote server doesn't seem to exist, even though it would be a perfectly feasible thing to provide.

You've pointed this one out at least once Ian: Facebook as a medium. I think many would agree that Facebook as a platform could have evolved into a really remarkable way to socialize and interact with other people and other businesses, but instead advertisers (mostly) have limited its use to focus on clicks and impressions to gain revenue rather than meaningful social interaction.

I've always thought iconography deserved attention for the way in which it seemed to me to transform from a visual expression of scripture to an object of worship. The tension was arguably the cause of the iconoclastic movement in the Orthodox Church as well as the critical position taken by Islam. Perhaps if the early Church had taken a more explicit position that visual representation of scripture was a useful tool to make it accessible to a mostly illiterate audience and that you would no more worship an image than a traditional textual description of some event, a scholastic tradition of media theory could have subverted the various icon-related conflicts that sprang up later.

Media theory as cure to sectarian violence?

@Nick
Definitely some related examples from Lessig there. The discussion of the role of regulation and lawmaking (which is what we'd expect from him) does make sense, and shows how a medium is not just the medium itself, but also the legal situation in which it can or cannot operate.

@Jason
Great example. And the persistence of a small community of radio hobbyists does offer a sense of what might have been had it been allowed to operate on a large scale.

@Mark
With respect to film, it's interesting to ask what role propaganda film had in expanding the perception of uses for the moving image.

@glenn
Your comment about the Cloud and Facebook reminds me of the "friend-of-a-friend" or "FOAF" trend that was nascent around the same time as blogs (2002-3). The idea was to create a way to identify a social network (nobody called it that) in a local fashion, modeled after the way a web server worked, rather than in a centralized way, which of course became the norm.

@Elijah
This is a really interesting example that relates to a project in its very early stages. I also find pre-industrial answers to this thought experiment to be particularly compelling, if only because they stretch our minds more than the familiar media of the twentieth century.

Reading. It might be an example of a reverse sequence. During European theocracy, silent reading was highly illegal. One was only permitted to read aloud, especially if one was a cleric at a lectern. By the late sixteenth century England had a literacy rate in the 90 percent range, which has never been surpassed, because Puritans wanted to read silently.

Nice one, Tim.

There's also Tim O'Reilly's definition of "Web 2.0", and its subsequent bastardization. If you were going to talk about the misuse of the Internet, that might be the best place to start.

I seem to recall reading that early telephone use, in which the emphasis was on business-related calling for "the man of the house," in order to conduct business more efficiently. Housewives were discouraged from using it as a result. It was not until later that the phone-as-personal-tool became common/popular.

(I'm not sure I could point to my source, though.)

The first media misstep that came to mind occurred in early printed books. The mindset behind early editions of print books was, most often, to make money out of presenting new editions of old works that still looked like they could be in manuscript form. This is most evident in the typefaces used, many of which were based on scribal hands and included features that were unnecessary outside of handwriting. It took some time for these types to be replaced by types that were cleaner in presentation, ones that we today find easier to read.

@James
I can imagine early typesetters invoking the argument from historical aberance in their justification for avoiding non-hand-written typefaces.

But that didn't "win out over a more appealing or promising" use of the medium.

Hypertext, the WWW and browsers are obvious cases in point.

Read Ted Nelson re: WWW/HTML: "The Web is the minimal concession to hypertext that a sequence-and-hierarchy chauvinist could possibly make. The Xanadu® project did not "fail to invent HTML". HTML is precisely what we were trying to PREVENT-- ever-breaking links, links going outward only, quotes you can't follow to their origins, no version management, no rights management."

So WWW/HTML/browsers were a misuse of the opportunities of hypertext for Nelson – yet the WWW/browsers as they developed also were misusing the opportunities Tim Berners-Lee himself built in: Mind you, the first browser was also an editor. We needed the whole "2.0" thingy and additional layers of protocols to return to what was there as a potential to begin with.