Because of the case law nature of the US legal system and the informality of TM, if other people start using the term in other ways (for example using "xerox" as a verb meaning "copy") and you don't show an effort to curb that then you can lose your trademark.

In other countries things are different. Brazil, for example, uses a Latin legal system which is more formal. So the only thing that matters is whether you have registered the trademark with INPI (National Institute for Intellectual Property) or not. Which is why Gradiente owned the iPhone trademark in Brazil even though they were not using it anymore (it was from a product from around 2000) and if you asked anybody on the streets in Brazil they would associate the name with Apple.

Which gets us to estoppel. Estoppel requires explicit consent and isn't transferable. You won't get estopped from a trademark suit because the person who was misusing the mark thought they'd get away with it, that's completely contrary to how estoppel is used. If you give permission to someone to use your mark, then you're estopped from suing, but I didn't say "Give everybody permission" I merely said there's no need to sue or threaten to do so.

Genericisation is more interesting because in some sense it's true, your mark might become generic. This is generally a huge success (you don't become a household name if nobody has ever heard of your product...) but it's also extremely unlikely and both escape mention in this sort of piece. Indeed some marks listed aren't "generic" in the sense we meant here. If your mark is "genericised" as penalty for your country starting a global war, that's not going to be fixed by suing more people.

As you'd expect, the attorney assures you that you should pay them to help, even though they list absolutely no way in which they'd actually be able to help. How would you create a "clear record of enforcement"? Are you supposed to ensure that the correct number of people somehow infringe so that you can go after them? How many would be too many, or too few? How will courts measure?

The answer is it's nonsense. "Enforce it or lose it" claims are caused by the fact that lawyers would like you to give them money, - most of them will stop short of outright lying to get your money, but misleading is very much fair game when you're not even a paying customer yet.

Genericisation occurs when ~everybody uses your word to mean a thing. Are you going to sue everybody? Is an attorney going to help you, somehow, do that, some sort of reverse-class-action? No. They'll gladly take your money in exchange for the advice that in fact you shouldn't try to sue everybody.

In passing: The word heroin isn't "Inherently distinctive". It's barely distinct enough (remember this is a German manufacturer, so think German) to have made a reasonable trademark for Bayer's "non-addictive" morphine. Which is striking actually: Hey, who here has heard a story about a supposedly "non-addictive" opioid medicine sold by a huge pharmaceutical company who knew they were lying ?

The LLM stuff is because this wouldn't even be the second time I've had a thread where someone insists LLM told them about all these cases which proved me wrong. Previously in one HN thread they were so convinced they just pasted the made up case names wholesale.