...same holds true for the sitemap. -- Really annoying that Nopcommerce doesn't just do things the way everyone else has them done. It wouldn't be hard to code sitemap [as a XML] and Robots [as a TXT] file generation based on settings. After all, it's what all webpage creation software do out of the box.
Yes, it is really annoying and it is a must to have an extendibility point from which every plugin should be able to modify the Robots.txt file.
I think this should be suggested to the nopCommerce team.
Thanks for your feedback !