Let me get this clear in my head - you want "Full Stack Developer" to be someone well versed in everything that is happening from the assembly running on your machine to the browser, to the network stack and routers, down to the server, and back down to the assembly running on that server?

It would be a good interview question; it would filter out a lot of bullshit because, frankly, anybody who says they understand that for all permutations of those components is a liar.

There are very few people who would be able to even give you a 10,000 foot view of all the components that make up the delivery of a web page from end to end, let alone truly understanding all of them.

To borrow from the article - there's too many abstractions.

No, not really. Even Hanselman does not say he's well versed. It's a general understanding. I wouldn't expect a full stack developer to be able to whip out a GUI app using nothing but assembly during an interview, but I would expect them to understand that missed branch predictions thrash the instruction cache, what object files are and how a linker works, what a normalized database schema looks like, basic ipv4 networking etc. These are all wide swathes of knowledge. If someone claims they are 'full stack', what stack are they talking about? Serving web pages? If that's all it is, wouldn't 'web developer' suffice?

"The full stack developer brings the SaaS cloud to you with webscale!"

It even sounds like marketing garbage.