My memory from the time was that the OSI was mostly about trying to characterise the various licenses that were floating around, and about legitimising the use of freeish software in industry.

Today the majority of free software that I use seems to be Apache/BSD/MIT - and GPL for Linux - but back in the 90s everyone seemed to make up their own “free” license, and there was a lot of confusion around GPL. My recollection is that OSI was trying to create some clarity around which licenses really were “free”, and which weren’t.

I was just a passive observer, I was not involved in any way, I wasn’t a fan of some of the players, and I even thought calling it OSI was pretentious - but nevertheless they made a dent in the universe by popularising the term “open source”. OSI was far more than a rebranding because it enabled us to speak about GPL - which imposes conditions on use - and free licenses like BSD in the same breath, while excluding what we now call “source available” licenses.

So despite my misgivings, I think the OSI deserves credit. They stood up and did something meaningful, and helped move the entire software industry forward.

Because of this, I think calling it a rebranding is totally unjustified and unfair.