Actually, that's not true. ReST was developed in parallel with HTTP 1.1. It used the basics from HTTP 1.0 to express some of the new ideas. You can read about the original idea in Fielding's disertation here: http://www.ics.uci.edu/~fielding/pubs/dissertation/rest_arch...
If it were an extraction of anything, it wouldn't have been HTTP but existing ideas in scaling web architectures in general at the time.