Gatekeeping is restricting access to the trade with arbitrary precedence, like "real coders use emacs." It's not expecting safety. If someone wants to build a bridge out of cotton the city won't let them. That isn't what most people consider gatekeeping.
Vibe coders as described in the OP can just copy/paste exactly what the LLM spits out with much less knowledge. It’s not the same thing at all IMO.
If you only take exactly what the LLM spits out you can only verify by running. If it is broken in edge cases you can only prompt the LLM to fix. You then have to run the code again to verify the fix, and with zero understanding it may have broken some other edge case (LLMs do this all the time especially overly eager reasoning models).
It might be, it might not. My colleagues and I are also guilty of introducing unrelated edge cases, but again, we do fine.
The case you're describing is also fairly pathological. There's nothing stopping a vibe coder from digging into their code and becoming a 20% monster like me.
When a post is a "warning" about user's credit cards etc. and it was in none of the "vibe coding" examples, that feels like someone deflecting (but with a gate keeping mindset).
As others have said here, I too have knocked out little apps and sites vibin'. At first (1) it was to see if what everyone was saying about LLMs was true. Then (2) I wanted to see if LLMs could help in languages I was not familiar with. Then, even for languages I knew well enough, I (3) wanted to see an LLM's code to get the modern method of modularization for the language (JavaScript is one that has gone through phases). Finally I came to trust the machine and (4) have vibed code just for my own small projects.