I'm not sure if you're saying one shouldn't use a SQL database at all or you're saying that using SQL as a user facing query language is bad. In this case, I t

I'm not sure if you're saying one shouldn't use a SQL database at all or you're saying that using SQL as a user facing query language is bad. In this case, I think it's better to consider the user facing language as a simple language that roughly looks like SQL. The author has exposed a very trivial amount of the power of SQL, so a lot of languages would fit the bill.