Jon, 20 month old babies cannot be supervised 100% of the time. They're walking by that age. You turn your back for 5 minutes and those beads are gone.
When you have a kid, you child-proof your home. You put the little locks on the cabinets, you put the covers over the door knobs. You put the thing over the toilet. You do this, not because you want to be able to leave your child alone for hours on end without supervision, but because toddlers can get into stuff faster than you can blink.
Chewbubba has an excellent example. You buy these toys for a 5 or 6 year old. He/She is playing with them on the counter. You also have a 2 year old. The 2 year old waddles over to the table, reaches up and grabs a handful, and crams them in his/her mouth. You see it happen, so you run over and try to get them out, but by the time you get there the kid could have very easily swallowed several. Even more likely if they taste bad, because the kid is more likely to swallow them to get the taste out of his/her mouth than to hold them in his/her mouth. Now, imagine that you're using the restroom while this is happening (or preparing meat to get dinner ready, or any # of things). Suddenly, you're not in a position to run over and stick your fingers in your kids mouth.
Worse, once the kid has swallowed them, 90% of parents are going to think "Well Billy's not choking, they're just beads. He'll poo them out." Next thing you know, he's acting funny and you have to take him to the ER.
If you choose not to decide, you still have made a choice.
Lassev: I guess there was something captivating in savagery, because I liked it.