However, that doesn't mean that people aren't learning it anymore. They're just starting with a broad set of high-level knowledge and drilling down into the parts that are important to them. For instance, recently I've been toying with compact string representations of big integers (using bit shifting: how topical).
The end result is that you end up with developers who have broad knowledge of the higher layers of abstraction but incomplete and specialized knowledge of the lower layers. That seems perfect to me.