2: if the tools were open source, people would be free to improve on these bags of pain that we have the pleasure of spending thousands of dollars per license.
So you not only want open source hardware specs but open source existing tools? I don't see intel open sourcing icc, or other software devlopment centric companies open sourcing their IDEs - ao why shoukd FPGA vendors? The original point was allowing open source tools to be developed like gcc, and the response was that it has not happened despite some ground up tools do exist but are very primitive.
I'm not sure that the OP was stating that it is a requirement that the FPGA manufacturers open source their tooling, only that the devices be well-documented (without NDA requirements) so that someone could have an opportunity to do so without the imperfections that reverse-engineering a production can entail.
To your example, 'I don't see Intel open-sourcing ICC'; while it would be really nice if they did[0], it's not a requirement in the same manner that it wasn't a requirement for gcc to exist.
I could be wrong here -- I do not develop for the FPGA space, however, I've run into similar problems all over the embedded space. Try developing something on one of ARM's Secure MCU products that lands comfortably in just the "open-source software" category (skipping hardware all-together). It's...tricky. To get details on the design of the security features of these products, you have to execute multiple NDAs. And this is in a security space where openness is considered a security feature. In theory, at least, if you interact with one of these NDA-protected features, publishing the source code might be a violation.
Unfortunately, I suspect that many of these features are as good as the secrets that are kept[1] -- exposure of the documentation would likely yield viable attacks[2].
[0] Not the least of which would be to be able to port some of the optimizations that icc enables for Intel processors but disables for AMD/others to be able to be used on...AMD/others.
[1] To clarify, I have not signed any NDAs with ARM, so this is entirely speculation. I'll be a party to one, shortly, so I won't be talking on the subject assuming -- as I suspect -- that doing so would run afoul of the NDA provisions.
[2] At some point the hardware world will learn from Intel and others that security through obscurity ...isn't. As with Intel, as far as we know, the issues they experienced with their management component existed for years without breach. The vulnerability was shockingly bad, was almost certainly known by adversarial governments and black-hats, who kept it a guarded secret as carefully as Intel kept the details of their management component secret. So they succeeded in keeping attackers in business and customers in the dark ... making everyone feel secure.
2: if the tools were open source, people would be free to improve on these bags of pain that we have the pleasure of spending thousands of dollars per license.