Fuck that would be awful.

I have 0 stars on Github. Don't use twitter. Don't have a blog. Only a few coworkers I even talk to.

I spend my time writing code and interacting with my family, not trying to win popularity contests. Now if you're looking to hire celebrities instead of programmers, you're maybe onto something. I'm not a self-promotion artist. If I were, I would work in advertising.

Twitter and blogs would be an excellent approach for hiring marketers/growth hackers

Being trusted by your peers is different from trying to win shallow popularity contests.

That kind of aversion towards self-promotion might be a reason why we arrived at absurd phenomena like homework assignments for interviewing processes in the first place.

With no way to draw upon previous work results or third party trust how else is someone supposed to assess a candidate’s skills?

If people did previous work, you should look at it. There's a way to do that. Now, if you can't because of the industry's propensity for using the law to hide information, then it seems that may be the cause of the industry's inability to find relevant information about potential employees.

Number of Twitter followers is now an indication of third party trust?

For the software industry ( for other industries or use cases that might certainly be different) I think it is. It’s just one possible indicator but an indicator it is.

If I come across or meet a new person from this industry and that person has a Twitter account I routinely check the follower count.

A somewhat large number says to me: “Many people seem to think that person has something relevant to say.”

More realistically, a somewhat large number (>1000) says to me "this person spends time and energy on self-promotion". Some of the smartest people I know have Twitter accounts with just 100-300 followers because they don't aggressively blog or anything.