I think RDBMSs will always feel slightly "special-case"-y when compared, as you seem to be doing, with general purpose programming languages - remember that SQL

I think RDBMSs will always feel slightly "special-case"-y when compared, as you seem to be doing, with general purpose programming languages - remember that SQL was never designed to be a turing complete language (insert someone showing it doing CTE tricks that make it so...). It instead exposes a number of primitives that a database is generally good at reasoning about and in return it can "see through" a lot of the queries the user writes and find efficient ways of performing them. If you want a general purpose language as your database engine, you'll likely end up with something more like MongoDB where for any moderately complex query you'll end up hand-writing a single static query plan for everything. This is probably why people seem less fussed about some of the asymmetries you identify in RDBMSs. Different philosophies.