At what point (if ever) would using a photo like this fall under fair use? The author doesn’t seem to care, but I’m curious if copyright is ever forfeited due to widespread use or inaction of the copyright holder.
Enforcement and collection of the damages is a totally different issue.
As for fair use: if you were to criticise something related to the image (say, you make a whole youtube video criticising the blog posts on this website and this image scrolls by when you do a quick lookaround on the website) or make some kind of transformative art out of it and the author would sue under DMCA or similar and the lawsuit would be based on US law, fair use would probably apply.
Fair use is a defence to use in a lawsuit, after all, not a right, but you can definitely do things with this picture that would be defensible under fair use. Companies specialising in copyright would probably try to convince you to avoid a lawsuit and come to a mutually beneficial agreement before the thing is settled, though, because big media companies do not like it when copyright law and things like fair use get defined (and thus consumer rights may be gained, and the excessive wealth of the media industry might get dented).
What the pirate bay did could never really be construed as fair use. At best, they can claim to simply host links, no content, and should not be held accountable for the illegal behaviour of the users and searching clicking said links, just like normal service providers. That's not an exemption in copyright law, though.
The statutory fair use defense codifies a Constitutional (First Amendment) limit on the copyright power found by the courts prior to the existence of the statutory defense, so it is both a defense and a right, specifically, the Constitutional right of free speech.
Lawsuit defenses, more generally, are assertions of rights, whether statutory, common law, or Constitutional.
It fails this part of fair use: 'The purpose and character of the use, including whether such use is of commercial nature or is for nonprofit educational purposes. Courts typically focus on whether the use is “transformative.” That is, whether it adds new expression or meaning to the original, or whether it merely copies from the original.'
Taking a step back, why not? Even (especially) real estate gets forfeited like that. It seems like the mp3s I've had for 20 years should fall under adverse possession. Or if you'd like a higher bar for openly possessed, then torrents have that have been publicly seeded for multiple decades.
Trademarks, certainly, but not copyright.
If the copyright holder knows its being used, and doesn't attempt to enforce copyright rights, but after a decade or similar, changes mind and starts enforcing, the court might rule that copyright is no longer enforceable.