Talk about software lifecycle.
I wonder if there is much of a community around this software and if there is someone who may take over the future direction, much like how Emacs' head maintainership was recently (relatively) given up by RMS.
Frankly, it sounds like your suggesting that because he didn't invent the underlying network stack, or network protocols, that makes it a quick and dirty half day or so project. 99.9% of development work in recent years hasn't been inventing new stuff, it's been building wrappers. Wrappers that compose other well though out tech (which are hard choices to make), while maintaining the flexibility to actually be useful for more than a single project and a short period of time.
I know you said none of those things, however, that's what I read between the lines of a putdown comment like "It's just a wrapper...".
Nothing wrong with a wrapper of the underlying system has had the real world field testing, longetivity, and adoption that IPTablws has.
On a side note whilst many people fail to deliver a side project they have spent a few months developing this man has been released and developing his for 20 years which I believe is praise worthy