Jackdaw, I think that Gore certifies manufacturers' fabric constructions, and then warranties the result. There's something like "if your fabric meets these requirements, you are allowed to put our silver level GoreTex patch on it, or gold level patch, etc. and then we will warranty for life." So, yes, I agree with you. GoreTex is definitely a membrane sandwiched between fabric, as opposed to a coating applied as with other brands of waterproof breathable fabrics.
Having grown up in Delaware, home of DuPont, and having had family work for DuPont (heck, my Mom met my father at DuPont, where he was a chemical engineer...) we know people who took DuPont innovations and started their own companies. For example, Mom was friends with the guy who took Tyvek sheet and started making mailing envelopes out of it. And, of course, Bill Gore was the guy who used Teflon (PTFE) to make wiring insulation, and his son Bob Gore figured out how to heat and stretch Teflon to create its microporous structure that allows water vapor to escape, while remaining waterproof. I have friends who worked at W. L. Gore. My Mom knew someone who worked at Gore back when I was a kid, and she got a bunch of off-cuts of cosmetically flawed fabrics. Haha, we made a wood carrier sling out of GoreTex fabric to carry wood in to the wood stove, because Mom had it hanging around in a box. I remember she made me a jacket out of some of it. Wow, that was LOOONG before I worked in an outdoor equipment store and learned about high tech fabrics... I remember my Grandfather doing commercial photography for samples of weathering accelerated panels of Imron paint showing no discernible reduction in shininess. As a matter of fact, the photo in question had 3 Stanley tape measures in front of the 3 Imron sample panels, showing the reflection of the tape measure. I still have one of those tape measures that Granddad gave me!
Wow, thanks for letting me go on that trip down memory lane. DuPont was so important to Wilmington, DE, and people I knew. It bothers me now to hear how they are trying to merge with Dow Chemical in search for more "shareholder value." Grrrrr... don't get me started.