I love it! I liked it so much that I pasted a print of the editorial into my notebook just in case I want to show it to someone in the future! 🙂 I'm glad you shared it, because I agree "Only a data geek could have this much fun with a piece or two of junk email." 🙂
Of course, the serious points are that although NULLs can be a bl**dy nuisance in SQL, they also serve a valid wider purpose, which is to represent the cases where "We don't know the answer to that question" or "We can't know the answer (because the question doesn't apply)" or maybe a few other things.
Dealing with those situations makes people feel uncomfortable and too often the answer is to brush it under the carpet and cause things like "Andy NULL".
I guess many NULLs represent a compromise or a simplification in the data model or a problem in the data acquisition. It is rare that there is a realistic opportunity to remove them altogether from the database. The problem (which isn't restricted to SQL) is explaining the consequences to the uninitiated in a way that doesn't sound patronising and say that the options might be limited to saying you have to exclude the affected records ("Sorry, you can send mail to customers like Andy"), or that you have to substitute some sort of default. Defaults are great if you convert a missing "Middle Name" to blanks or "empty string" in the application, but not too great if you convert Andy null to "Andy NULL", and just plain "Andy <blanks>" is scarcely better.
Of course, there is a whole new level of strangeness when people start trying to do arithmetic with columns containing NULLs, That might make an interesting topic if anyone has some good examples.