Yes, Absolutely, Without Reserve.
First of all, at the risk of repeating myself:
Users Should Downvote However They Want
Downvoting on Stack Exchange is anonymous for a reason. As long as a user is not abusively downvoting (that is, they are targeting a specific user, and not the questions themselves), SE has always quite openly asserted that users can downvote whatever and whenever and whyever they want.
The Help Center gives reasons why you might want to downvote, or why most people downvote, or what downvotes were invented for. But those are always just that: guidelines. (If we're going to start demanding everyone follow the guidelines to the letter, I have some scope and tagging discussions we can revisit...)
In the end, trying to tell users how to downvote is always wrong.
Votes Are How We Encourage Questions We Like
If I see a question that is so uninteresting that I think it devalues the site just existing, of course I'm going to downvote it. I, as one single user with one single vote on SF/F, am entirely within my rights to do that. It means I don't want you asking these stupid questions anymore.
If I'm the only one who feels that way, then the system registers my -2 rep points and everyone else moves on with life. If dozens of regular users feel that way, though, the OP gets a pretty strong signal that the community doesn't like these kinds of questions, and hopefully, stops asking them here.
That's exactly how a community-moderated site is supposed to work, and it's why votes exist. We upvote questions if we want to see more questions like it. We downvote questions if we want to see fewer questions like it. Whether that means it's well written, or detailed, or interesting, or even if that means "I hate that movie, stop asking about it here", whatever you define as "good" and "not good", that's how you vote.