This is why I've sold or will sell many of my more controversial books/authors for relatively cheap because, yeah, an extra used copy in circulation is possibly one or more fewer new book sales that author won't profit from. Some of them I don't mind if someone else enjoys that book itself for what it is/was at the time it was released, but it's nice to think that it next sale(s) might be a dollar or three the author won't see when they read that.

Most royalties are calculated on the initial sale of books to the store. This pettiness will have zero impact on the original author. You might harm some book stores by making it harder to move their purchased stock for which the royalty has already been paid.

Booksellers that overstocked the "wrong" books have ways to return stock to the publisher. Publishers will try to recoup losses from overstock in various ways, including withholding future royalties or dropping future projects from authors.

(The way of overstock returns I was most fascinated by as the type of kid who loved deep dives into weirder parts of the libraries is that some libraries have an "illegal" section of books that they literally dumpster dive local bookstores for. These books had their original covers removed, which is the simple, minimal way how the bookstore "marks" them as unsold/unsellable/"destroyed" before tossing them in a dumpster, because by that point even the publisher doesn't want the overstock physically back collecting dust in a warehouse, but also still needs a good relationship with bookstores. Many publishers still to this day have some form of wording in print books like "if this copy was found without its original cover it is to be destroyed and is illegal to be resold". The bookstore would get some form of partial refund on all the "destroyed" overstock.)