You're completely correct that the original meaning of the term was specific. Eric Ries originally wrote, "I want to introduce the concept of the pivot, the idea that successful startups change directions but stay grounded in what they've learned. They keep one foot in the past and place one foot in a new possible future. Over time, this pivoting may lead them far afield from their original vision, but if you look carefully, you'll be able to detect common threads that link each iteration. By contrast, many unsuccessful startups simply jump outright from one vision to something completely different. These jumps are extremely risky, because they don't leverage the validated learning about customers that came before." [1]
Sadly, the term is getting killed by Semantic Diffusion [2]. Precisely because people want to dignify their flailing with a fancy-sounding word.
[1] http://www.startuplessonslearned.com/2009/06/pivot-dont-jump...
"Affordable wireless networks" somehow became a food company.
http://blog.soylent.me/post/51007573199/the-biggest-pivot-in...
If I remember correctly, the creator of soylent invented it for his own needs, blogged about it, then was stunned by the amount of interest.
In this case, it seemed like the idea kept changing before they had even figured out much about it, or had any evidence to justify a different direction.