I see the learning curve as being a lot higher for kids these days. Computers are more accessible and prevalent, but the amount of effort to get something running, even "Hello World", is much higher.
Someone (was it Bill Atkinson?) once said he wished HyperCard was built into the ROM of every Mac. I wonder what the world would be like now with a whole generation of kids playing with hypertext and simple OO concepts.
When the learning begins at a higher layer of abstraction, some knowledge is necessarily left-out. Perhaps it is done so for valid reasons such as relevance as you mentioned. However, to master a point at a high level in any stack you do need to understand or appreciate the lower levels as well (which might be harder for kids today).
Understanding it requires at least one brain with at least 8 dimensions and human brains have only 4. It also helps if your sensory organs are evenly spread across all 8 dimensions.