A now-closed question about grammar, ("As pets being welcome, she stayed at the hotel with her dog.") while not well expressed, fell squarely within the top two topics listed for ELU:
Questions on the following topics are welcomed here: Word choice and usage, Grammar, ...
The OP presented two valid grammatical constructs alongside a third construct that improperly mashed together elements of the first two. On its face, the question was whether the third construct was valid.
The question could have been better articulated, but it certainly was a good question. It went beyond basic usage, and required more than rudimentary analysis. It implicitly sought an explanation as to why the third construct was improper while the other two constructs were ok.
One of the comments of a user voting to close the question was, "about whether something is grammatical, not about grammar; removed fluf." The other comment was, "Not suitable for this site."
While the OP didn't explain their motivation, it was clear enough that they were asking, "Why are these two constructs ok, but this other construct not ok?" That is a question about grammar.
Perhaps the list of topics needs to be revised to better explain the nuances between desirable questions about grammar versus undesirable questions about whether a particular sentence is grammatically correct. Also, the popup guide in the question composition user interface could do a better job of alerting new users about that distinction.