Why did LEGO stop selling sets for <1.5 year old (Primo etc)? LEGO used to make Primo sets and baby toys for 6 month+ babies.

As a parent of a young child the only option I have is Lego Duplo that isn't quite ready for her age. 

Are used Lego Primo sets safe for children? I don't get why LEGO only sells toys for children older than 1.5 years. Why did they stop?
I can't comment on why Lego stopped selling Primo. But I can assure you that Duplo is fine for children. The smallest pieces are way too large to choke on, as far as I can tell. Small babies probably don't know how to put the pieces together very well, but that doesn't stop you from building a little house or car or something and letting them play with it.