Just to clarify, I didn't say they're not easy to pull apart, just that they're not meant to be.

I don't think they're getting more powerful because they're not meant to be upgraded, but rather the elements of competition and consumer-stupidity. Most computer buyers don't know much about computers, and just lean toward the high-end machines in awe and forget the fact that they will never need all that power. If they needed all that, their desktop would be just amazing. I do think the upgrade thing is an issue, though.