[all this is of course just my opinion]
Tags are used by people to define the scope of their questions, and they should keep being useful that way.
The linux tag should be used when the OP only cares about information and solutions that apply to a typical GNU/Linux system, and doesn't want their question hijacked into a portability and system comparison discussion.
Similarly to bash when they absolutely don't care about portable shell scripts, and are perfectly fine with using features like arrays, process substitutions, etc.
Trying to micro-manage tags and turn them into a curated ontology completely destroys their utility. The linux tag should only be force-added to another user's question when it's absolutely clear that any relevant answers could only apply to Linux-based system, not when they just mentioned (or it could be guessed) that they're using a Linux system, and should not be force-removed unless it's clear that the user is confused and they're not using Linux in any way or form.
Just in case it wasn't clear enough, I reject any pretension of "consensus" for blacklisting the linux tag -- as long as you're not going to ask all the people who already tagged their own questions with the linux tag in the way I've described it, and you absolutely don't care about its effect on new users asking questions, I'll consider this just a way to enforce the groupthink of some close-knit club of users. Or worse.
Removing the linux tag could only make sense if GNU/Linux is assumed as the "default" system -- it that's the purpose of this, better be crystal clear about it.