Why is sustainable development a more acceptable focus for education in the 21st century than conservation?
If this is true (and there are those who would argue that it is not), it is because the economic pressures of the 21st century make conservation much less feasible.
In past times, there was much less pressure on countries to maximize their use of their resources. One major reason for this was that population sizes were lower. Fewer people meant that there was less need to use every bit of a country's resources to satisfy its people's demands. Another reason was that so much of the world was poor. Today, there are more people and they are becoming wealthier. This means that they want to consume more goods and services.
With these greater pressures, conservation becomes less feasible. It is much harder to simply wall off various areas and prevent them from being exploited economically. Instead, becomes more feasible to try to use resources, but to try to use them in a sustainable way.