But advice really depends on the context of the person: what they've done, what degrees they have, what type of job they're looking for, etc. But to address the type of people the "show me the code" response is geared towards: instead of a github profile I would say build actual products.

Code in isolation is hard to understand, even to the point where its nearly useless. But having a couple of full blown web applications that do something useful shows all an employer needs to know (even if they have 0 users). Everyone can understand actual sites that look polished and professional, and shows that this person will bring value to the company (whether from a business perspective or from being a competent programmer). Good coding practices can be taught or enforced through process, but being able to construct an actual non trivial product is what employers really want.

How the code actually looks is less important than what it does. Of course, feel free to put the code on github if you want, there are some interviewers that might consider that a bonus. But for most people its too much effort to make any practical sense out of what they're seeing. Just a repository of code without any context doesn't help.

(Non snarky response) I dunno. I joined Google in 2008, and as far as I know Google was always like that. So, unless you claim developers have preferred Facebook etc. to Google for more than 5 years now, it's probably not related to the interview process.