The general rule I've seen around Stack Exchange is that a community is sovereign in deciding its scope¹, as long as it makes a modicum of sense. Stack Exchange employees may enforce quality requirements, for example by closing questions that are “bad subjective”. But scope — deciding what questions are on-topic or off-topic — is decided by the community, through meta discussions.
As a moderator on several Stack Exchange sites, I've always felt that it was within my mandate to crack down on low-quality questions whether the community acted or not, but that deciding the scope was solely the purview of the community. I do of course participate in debates about the scope, but I'll enforce whatever the community decides. This is what I've seen practiced on other Stack Exchange sites except sometimes on the Trilogy (SO/SU/SF).
Yet, one week into the private beta, with no prior warning that I am aware of, a Stack Exchange employee closed at least 15 questions (about 1/8 of the questions to date) with the following comment:
"Hardware Recommendations" was created for questions seeking a specific hardware products given a set of definitive requirements. If your question involved general computing or hardware issues, it can likely be asked on Super User; but nevertheless, it is outside the scope of this site.
This statement about the scope directly contradicts the meta consensus around
Are “What should I consider when buying” questions allowed?
(…) I think, they should be allowed and in fact be encouraged.
After prompting, the employee expanded on this statement in a meta answer on the aforementioned question, rejecting any debate around the scope:
But what we absolutely cannot allow to happen is to turn this site into an "alternative Super User"… a site where you can ask your hardware questions which also happens to allow product recommendations too. That just cannot happen.
Some of the questions that the employee closed were reopened by the community, but the employee closed them again (despite the meta opinion not having changed in the meantime).
Why are we not allowed to decide our scope? To use Stack Exchange's own language, why are we not respected? As far as I'm aware, it's a unique departure from the general rule.
And why does the crackdown happen without any prior discussion?
¹ Excluding content that's inappropriate, e.g. NSFW.