Because its not an issue any more. The world wide population is stabilizing. Most countries of the earth will face a population collapse in the next 30 years.
Sorry, this is bullshit. Even the UN estimates slowing growth for the next 80 years, but not a "collapse" or anything near that. And historically growth projections have been to low, so there is a fair chance the world population will continue to grow substantially for the next 100 years.