So, why bother? what's the point of learning how to make batch file viruses? Their practical potential is next to nothing, they are easy to find, easy to delete and spreading them is out of the question.
It's a start.
That is pretty much the only reason that batch file viruses are important. They are taught all over the world in various hacking courses for good reason. Every hacking forum, every comment section below a hacking video or a blog is filled with people looking for a way into the vast hacking universe. This is it. The more "out of the box" a virus or a malicious tool is, the harder it is to pin down and identify. But to get to the more complex stuff, one needs to master the basics first. Even though something like the innocent little batch file viruses don't have that "oomph", they pave the way for greater things. You probably can't take out every computer on the internet with batch files, but you will be able format an unprotected computer, you will be able to shutdown a computer every time on startup etc. This may not be enough "reward" for most people to put in the effort, but without a foundation you can't hope to soar high. Rome wasn't built in a day and so is the case with anyone's hacking skills. Everyone has to start somewhere and there's no better place than batch file programming.
As an added bonus, batch file programming is ridiculously easy. Barring the likes of HTML and SQL you will never see another sentence with "programming" and "ridiculously easy" in it. (For more on this, see "Programming -I, II" in "In too deep").
Learning how to make batch files gives you a glimpse of the much more complex world of advanced programming as well as how basic viruses are made and how they work. Lastly, no security system is completely foolproof. Unseen things can and do go wrong, which is what hacking is all about and who knows perhaps you will be the one to find the next big loophole.
Although this website will always be getting updated with more and more batch file virus tutorials (and more), below are a couple more sources if you'd like to "go beyond" and learn more on yourself:
Below is a link for a small book on "Batch file programming", in PDF format. At approximately 150 pages, it covers up pretty much everything you will ever need when creating batch files or working with DOS.
Also, here's an excellent but not so well known website with great quality and quantity of information on batch files: