> where people put in insults because they’re offended you asked them if they would like to subscribe.

It's a bad thing because people don't like the resulting UX, as your experience indicates. Interesting that Substack is aggressive enough in pushing folks to subscribe that they need to build subscription blocking because people hate the nagging so much they submit insulting email addresses. You would think this would be an indication to both Substack and their customers that the UX needs significant work.