What happens if an image search engine picks up that link and follows it? It makes a mess. And if the image is hotlinked, then the browser can't handle it properly... Browsers can't handle a redirect to an HTML page from an <img src=...> link.
I don't fool around with wasting bandwidth on other sites. That's their problem. I prefer to serve up a simple, short, 403-Forbidden response, and worry about other more important things.
No. It is there because the generator or its author are taking the easy route, and not fixing the special case.
Avoid ".*" whenever possible. It is the greediest and most-ambiguous pattern, and therefore, the least effcient to process. Leading "^.*" and ".*" and trailing ".*$" and ".*" patterns are a waste of space and CPU time.
You can use a generator to get started, but don't count on automation for quirk-free, efficient code.