No, that is not a valid reason to close a question.
The thinking behind it might be a variation of the old "too localized" close reason. But that's a historical artifact we ejected quite some time ago, thank goodness. So let me provide a bit of historical context why we should not be rejecting stuff based on too hard or too specialized.
Historical background —
Way back in our earliest days, we envisioned a problem that, as it turned out, rarely occurred in actual practice — users asking about problems that were sooo obscure that they couldn't possibly be of interest to anyone else ever. E.g.
Why is there a green Honda Civic parked out in front of my house?
Who cares; right? "Too localized" was used to describe questions involving "…very tiny geographic regions or vanishingly small periods of time." But soon folks were using it to close questions with comments like: "This only pertains the people living in India, so it is 'too localized'" (← Yes, people actually said that). Overuse of this close reason was out of control, so we dropped it entirely, good riddance.
There are two reasons folks might find it desirable to close questions that are too specialized or too hard to answer. One is that it will bring down your 'percent answered' rate; the other is that not enough people on the site will actually have that problem. But it's actually quite the opposite — questions requiring "specialized expertise" are what make the best of our sites interesting. When a site fills with easy or overly generalized questions that have been asked hundreds of times on every other site on the subject, that's not very interesting. If the site doesn't bring something different to the Internet, that doesn't really bode well for attracting or keeping people interested in the site (but don't get me started about closing questions that are "easily Googleable" either. Oy.).
Certainly questions should not be closed because the average person cannot answer it. Getting long-tailed questions like that answered is what makes some of our best sites worthwhile. You need the challenge to keep this site interesting. A 100% answer rate isn't always a good thing, and if your questions are all easy to answer, then there's little purpose in having the site in the first place.