Part of the reason for this is the nanny state. The other part is that in this time where intolerance is the greatest evil that exists, having a child out of wedlock is not stigmatized as it once was. There is no shame anymore and shame is a great motivator to do the right thing.
shame can also motivate people to do the wrong thing. Sure, for some people it will keep them from engaging in sexual activity. For others, it will cause them to abort an unexpected pregnancy, so that no one will find out. I have seen an awful lot of bad things happen, because people are trying to avoid shame. A little tolerance is sometimes beneficial.