On the same basis, the following are dangerous in that they pose a swallowing risk, bear no caution on the product itself (sans packaging) and should therefore be banned:
1) Tyre valve caps
2) Used or discarded staples
3) Ball bearings
4) Nails
5) Screws
6) Rivets
7) Button cells
8) Toothpicks
9) Cotton swabs (what you call "Q-tips" in the US)
and too many other household things to name. Heck, if we want to absolve the parents of ALL responsibility, we might as well include packets of dessicant (silica gel) with a "DO NOT EAT" warning clearly printed on the packaging, on the basis that the children likely to swallow those packets are unlikely to read and/or heed that warning.
We have to be reasonable about this. At some point, we have to draw the line and say that parents should step up and be responsible for the safety of their children. When I was a kid, my toys didn't come with screw-on battery compartments. Now, every single one of my own kid's toys come with this "feature", and frankly, it's a PITA, because my son has never been dense enough to attempt swallowing one of his batteries. In fact, it's a completely unnecessary imposition because my son manages his own battery collection, has his own battery tester, and has a screwdriver to change out used batteries himself. The fact of the matter is, I did a risk assessment, satisfied myself that he fully understood the risks, and was smart/mature enough not to do anything stupid, and I let him have the freedom to do these things which modern children are apparently not "supposed" to be doing.
Let's stop mollycoddling the children, let's reintroduce the notion of parental responsibility, and stop blaming the least likely party for mishaps. Only then will there be real hope for society.
(BTW, I agree with the bans on some obviously hazardous things like lead paint on chew toys for infants, because there is no way to escape the hazard even with full parental supervision. In these cases, using the toy as intended carries a serious hazard. What I'm against is taking this sort of caution to the extreme).