This. The author also acknowledges that some of the languages they complain about are SQL dialects. Often they are simplified versions of the "generic SQL", e.g

This. The author also acknowledges that some of the languages they complain about are SQL dialects. Often they are simplified versions of the "generic SQL", e.g. AWQL does not have JOINs. Supporting all standard SQL features might be worthless and/or impossible for some domains.