I'm trying to think of examples of technologies that were innovative and basically worked, but weren't potent enough to overcome the skepticism eventually, and/or couldn't overcome the deadweight of externalities. 

Not potent enough: flying cars
Couldn't overcome externalities: nuclear rockets

Any others?

Blogger at ribbonfarm.com, running summerofprotocols.com, host of /gloom ☀️

Flying cars are not a good idea even if they would be technically feasible. Other examples that come to mind: supersonic jets, Dvorak keyboard, Linux for normies and torrents