You guys have closed a lot of questions lately:
SELECT year(Posts.ClosedDate) as y, month(Posts.ClosedDate) as m, cast (year(Posts.ClosedDate) as varchar(10)) + '/' + cast(month(Posts.ClosedDate) as varchar(19)) as ym, count(CONCAT ('http://programmers.stackexchange.com/q/', Posts.Id)) as Questions
JOIN Posts ON Posts.Id = PostHistory.PostId
WHERE Posts.ClosedDate >= '2012-01-01'
--AND Posts.ClosedDate < '2012-12-01'
AND PostHistoryTypeId = 10
AND PostHistory.Comment != 1
group by year(Posts.ClosedDate), month(Posts.ClosedDate)
ORDER BY 1 desc, 2 desc
There is another reason why I think you guys are indeed too strict. When you look at the results of the recent stackoverflow survey, you'll see that 20% of respondents are working in 1-person teams (Question 8,9). 36% regularly interact with customers (Q10). This is a significant fraction.
Most people consider themselves as "full-stack web developers" (Q7), which -in my opinion- means they have to switch context often and take over many roles -put on the frontend/backend dev hat, but probably also the DBA hat, the security guy hat. Each of these roles often happen after some interactions of working programmers with their environments.
This simply means that these people must interact a lot with non-IT colleagues to get the job done. Many issues derive from these interactions. They simply won't be restricted to questions specific to programmers.
If you still try to achieve that goal (only permit questions specific to professional software developers), so be it. Then I'd expect you to close, say, 30% of all questions. That's just an estimate off the top of my head.
However, this mindset would certainly scare away a lot of developers who post their good allegedly "off-topic" questions here. So if one's first question is closed, the chance is quite high to have the second question also closed.
And remember that saying "go away" to these turned-down "SE citizens" also contradicts stackexchange inc's business model, which is, to make money via careers.stackoverflow.com ... by helping out professional programmers to find a better job.