Just an excuse...
"Some countries have structured their IP laws in such a way that if you turn a blind eye, then you risk losing control of the IP."
Some companies maintian an iron grip over their so-called IP, up to and including suing fans.. and want to use this kind of law as an excuse to divert blame away from themselves by saying they are required to do this. They are not.
These types of laws do have a purpose.. Firstly, to prevent an unscrupulous company from sitting on something for years, and by inaction allowing people to either assume this item is public domain or that they tactily approve use of it.. .then popping up after years and suing everyone. Secondly, to prevent a company from accumulating so much IP they can't even keep track of it all, so they didn't know they even had the rights to something. Companies do both, but at their peril.
In this case, they are NOT really turning a blind eye. In the case fan items, as Craig 12 says, they are interacting with their fans. They aren't charging a licensing fee, but they are effectively maintaing control by approving of the items produced.. since they are in close contact, they could say "no" to some or all items down the road. As for the Asian counterfeiters, they say it's not economical to go sue each and every one of them.. but at least this means they have stated their disapproval for this counterfeiting. Both avoid the main peril under the law of saying nothing at all, losing control by letting everyone assume tacit approval. In one case they give explicit approval, in the other they give explicit disapproval.