As far as I know most fortune 500 companies would probably have similar reservations about these licenses (correct me if I'm wrong). Companies like TerminusDB switching license because "sufficient lawyers have advised teams to be wary of GPL" probably means that they were loosing lucrative deals with big customers because of the license. Hence the switch. I think dual licensing as a viable business strategy is pretty much dead at this point. An overly restrictive OSS license is a hard sell for a SAAS business in a competitive market with alternative solutions.
Legal interpretations are not an exact science of course but there's enough language in these licenses to cause raised eyebrows for lawyers and probably not enough court cases to argue one way or another definitely. That equals a lot of uncertainty and corporate legal departments hate that sort of thing. GPLv2 has had some exposure in courts over the years so lawyers are more comfortable with it at this point and know how to limit and contain its infamous viral nature.
I've also seen blanket bans on all GPL related licences in code (the dynamic in OS/app/other use differs, though way-back-when there was enough FUD/misinformation that there were blanket bans for those too) especially when GPLv2 was introduced (the "liberty or death" aspect was the cause of much consternation, I recall).
I don't think they are interpreting the license differently though for the most part. They are agreeing that is protects the user not the producer, and in giving those protects to the user it might be inconvenient for them (or even impossible for them legally, depending on licensing agreements and other restrictions they have to operate under regarding other parts of their codebase) as a producer.
> In other words, they weren't amateurs; like us.
At least some of the original impetus for the GPL was to protect amateurs like us from being used as free resource for parties that aren't. I'd say this is the system working.
> I think dual licensing as a viable business strategy is pretty much dead at this point
That is quite likely true, but only relevant in such a commercial context. If a developer doesn't care about commercial users of their code, for instance they are scratching an itch & want to share but aren't seeking worldwide adoption (and hold those "outlier opinions on freedom related topics"), then this is not a problem and GPLv3 is still a relevant option on its own.
Commercial viability is not the be all and end all of licensing decisions, if commercial gain and massive reach are not your concerns.
A common mistake in interpreting the GPL in my experience is that it is designed to protect the freedoms of the producer. It is explicitly designed to promote certain freedoms for the user. The producers set and the users set are likely to intersect, which is likely where some of the confusion comes from, but it is not common that they are identical sets.
If the corporate world is part of your target audience, then the GPL family, particularly AGPL and GPLv3 (though not so much so LGPL) are unlikely to be good choices. This is true whether you are a solo home developer, or a significant commercial entity, or something in between, yourself.
Just like commercial licences, and other F/OSS licences, the GPL takes away nothing. It grants rights subject to the grantee agreeing to its other conditions.
> under reasonable terms
That is a very subjective thing.
If commercial entities won't touch something of mine because I've chosen to license it under GPLv3/AGPL/else, that is only a problem for me if I care whether commercial entities use it. They are free to try negotiate a different licence. Of course I'm only able to do that for my contributions unless others the project has taken contributions from have legally stated on the record something to the contrary, but that is no different than for a commercial project which has multiple otherwise independent contributors.