It's because we audit every author manually. We actually CAN click a button and magically add an author. However their book list would be a mess. There would be multiple editions, foreign editions, no order to it, the same book but with alternate titles, and just completely incorrect books that are not written by that author in question.
That's one of the big differences between us and other websites; we take the time to go through an authors list prior to making it public, getting all the correct books in there, making sure there are no alternate titles etc.
There are lots of mistakes made on other websites due to not doing this process. Often, an author is listed as writing a book even if they only wrote the foreword. If there is a common name, many books are often incorrectly attributed to that author. I always like to use the example of Matt Jackson, the professional wrester and All Elite Wrestling executive.
He has written exactly two books: an autobiography, and a children's book. Yet his page on Goodreads lists over 50 books as you can see below:
That is because of the system they use in that authors of the same name often have their books grouped together. And the problem is so many sites use Goodreads as their primary source, so they end up spreading this mis-information around the web. We take the time to audit every author prior to posting to make sure that doesn't happen.
If you don't find the author you're looking for on the site, just send a quick message via our contact system. We will then click that magic button, get all their books in, go through them all and organize them and only then, when the list is complete and accurate, will publish it on the site and let you know. Depending on the quantity of books and backlog we have, it can take as short as a few hours to as long as a week to add them.