No, it isn't. It is harmful for free software projects to blindly incorporate software with incompatible licenses. It is not harmful to write software with incompatible licenses. Most software written is incompatible with Debian. With very few exceptions (for instance, the sole-sourced drivers to popular peripherals), none of it actively harms the project.
Debian is not entitled to Douglas Crockford's work and therefore Crockford cannot harm Debian through incompatibility. Someone else can write a replacement JSON library; it's an intern-level project.
How is anyone making that argument? From what I can see all people are saying is that making an obtuse licencing clause is a bit of an asshole thing to do. I can't see why anyone would disagree with that either.
This is one of those situations where 80% of the commenters in the thread will think I am trolling because their sense of entitlement to anything they can read in on a Github page is so powerful that they forget they're talking about the time and effort of an actual human being.
If you feel like you can call someone an "asshole" for writing "use this software for good not evil" in their license, then, and I mean this respectfully but directly, you need to unplug for awhile and interact with actual human beings in the world.
Similarly, if you can write a whole blog post calling Douglas Crockford "childish" and implying that he's not only a hypocrite but hypocritically evil for working at Paypal simply because of something he put in the license of a piece of software he gave away for free, you are a whackjob nutbag and nobody should listen to you.
Here is a clue before 8 different HN'ers explain to me how damaging idiosyncratic license clauses are and why that justified this nutball post: you can write a post about why people shouldn't use a specific free library without calling its author names.
Wow, the hypocrisy of using such poorly veiled ad hominem in an attempt call out what you apparently feel is mine, is almost comical. I'd ask you re-read what I said more carefully. It really wasn't nearly as extreme or insulting a statement as you seem to think. Certainly doesn't seem even remotely worth such personal ire.