There is an English game called “Aunt Sally”. The object is to knock the head off a dummy with a ball or stick. The version I recall most clearly was at a school fete. Good-natured teachers would dress in a ridiculous costume and sit immobile in a chair, while the public (including many pupils) would pay sixpence to throw sponges dripping with coloured goo at them.
For an author, listing a book on Amazon is a literary version of Aunt Sally. The public pay their sixpence and they can throw anything at you. It doesn’t even have to be a wet sponge — bricks, breezeblocks, poisoned barbs — all are acceptable. It would be churlish to respond; that is not how Aunt Sally works. Nevertheless, having one’s spiritual condition diagnosed and deprecated in public by a complete stranger is an odd experience.