Being a headless table utility, any screenshot of the table UI would either be over or under selling the potential UI that users will implement with the library. If you noticed the exmamples are very bare bones styles so as to highlight the functionality of the library. These examples would be "ugly" as marketing material. If another example was super dressed up and looked amazing and used as marketing material, users may be disappointed when they realize they are in charge of their own styles. It's 6's I believe, so I went with what I thought was the safest option, exclusion of screenshots.

I suppose then, a screenshot of source code next to the rendered output is what programmers desire, in the introduction. Instead of thinking "That's a sexy table!", the programmers will hopefully think "That's some sexy table-generating code!".