The article is specifically about sanitizing inputs to prevent XSS attacks. Sanitizing input isn't a great defense against that; you need a defense that better

The article is specifically about sanitizing inputs to prevent XSS attacks. Sanitizing input isn't a great defense against that; you need a defense that better matches the attack. Validating or sanitizing input input is a reasonably good defense against certain other things. E.g. zeroes in values you'll later divide by, when it's too late to return an error; multi-gigabyte names; information that you want to avoid storing like credit card numbers. That sort of use case doesn't really have a whole lot to do with the article, though.