By choice, I do not have a Play Store account and wherever possible install apps only from F-Droid. However, there are (rare) times where I want to install a free (as in beer) closed source app. However, the publisher only chooses to make the app available via the Play Store. I would really, really like a direct apk download. I appreciate this approach is not for every end user and some people are scared of the "warning" messages Android displays when installing apps directly. Nonetheless, it would be really nice to have the choice and I don't see it as so much extra effort on the publisher's side.