Again, the problem with replacing SQL with a more "relational" database engine and language is that, despite numerous attempts to do so, nobody has been able to come up with one that actually solves any real-world issues without causing more problems than it solves.

For example, on the point of 3-value logic, there are very, very few situations in this world that can be answered with only "yes" or "no" and that don't allow for "not sure" or "unknown at this time". Even Codd recognized this, despite his early opposition to the concept of Null values in relational data.

The problems with allowing nulls are purely academic. The differences between academia and reality are even more well-documented than the problems with allowing three-value logic in a relational database.

Here's my challenge to you on this subject: Write up, in detail, the actual situations in real databases, where the problems you have sited with regards to SQL have stopped you from modeling a real-world situation into a database. Specifically, I want to know the exact situation where 3-value logic being possible in a database has made it more difficult to model a business (or other real entity) situation. Note that that solution you were forced to hack must be more complex than simply setting the column to not allow Nulls. I want to see the same for each of the other "fundamental problems" you are citing. These must not be hypothetical situations, nor academic exercises, they must be real situations that caused real problems to real people.

I've seen this same set of arguments forwarded dozens of times over the years. It's not "met with resounding silence", it's met with "well, what real world problem are you trying to solve", which is usually answered by "well, nothing, but it's just not right".

If you can prove, in the real world, that these "fundamental problems" really are fundamental, and neither academic, incidental, nor trivial, then I'll buy your argument. Thus far, in a decade of seeing your exact statements brought up dozens of times, I've never seen anyone do this yet.