Earlier quoted context omitted.
They could just as well automatically chmod the txt/docx/html file to remove the executable bitset. Why would anyone want to have an executable txt file? If one does want it, it's pretty safe to let them reset the bit manually afterward.
> Why would anyone want to have an executable txt file? A shell script.
I meant to exclude scripts when I said txt/docx/html and likes. I understand I wasn't clear enough, that is my fault.