I kind of think being in beta and the fact there is much discussion about on-topic/off-topic sites, some mods are hasty to close questions without first determining the best place for it first.
Closing questions because they belong on another site is only one reason to close: one can vote to close because the question doesn't make any sense, only applies to the individual asking the question, or is off-topic even though there is no Stack Exchange for which the question is on-topic: "Is Justin Bieber Dreamy?" is an off-topic question and should be closed even though there is no Justin Bieber Stack Exchange site.
And the whole point of the "5 votes to close" functionality is so one person can't dictate whether a question should be closed: it requires four other people to agree with them. Five people independently arriving at the conclusion that a question should be closed is about the same amount of consensus that would achieved if we discussed each and every close candidate on meta first.
Just like a down-vote, regular users should be free to vote for close based on their interpretation of the rules of the site.
The only people who should otherwise be restricted—at least in principle—are diamond moderators because they can override any voting on a question. To diamond moderators, clear community consensus will be essential in guiding their actions.
Currently, there is a lot of consensus on what does and does not belong on the site, and we're currently hashing through the parts that don't. But we don't actually have any diamond moderators at this point, so it's not really an issue.