I don't think that's quite fair. It's pretty easy to know that COALESCE exists and still make the mistake.
A language should help you avoid making mistakes, not trick you into making them. The path of least resistance should be the safest and most normal thing, and SQL fails here.
I think it’s more unfair to say SQL “tricks” people into making mistakes than to lightheartedly see such a query and think whoever wrote it might not know about COALESCE. I see that query and the lack of COALESCE—in the context given where it is known the column we care about has NULLs—and assume there’s an opportunity to introduce someone to COALESCE: “Hey, check this out—it’s made for this situation!”
But saying SQL is tricking people into making mistakes? Nah. The real issue seems to be writing a query without a proper understanding of NULL, not being tricked by the language.
