I don't think it's a good idea...and I honestly don't see it come up that often.
Who actually posts questions on this site? It's not "non-IT" folks from other departments/professions posting questions, 99% of the time I'd venture it is someone in IT or at least been given the responsibility of administering whatever they are asking about (otherwise it's closed as OT, such as "my boss is blocking Facebook, how can I get around it?)
The IT person posting may not have professional expertise in the particular subject matter, but turning them away immediately without giving them the benefit of trying to help them out seems kind of cold and unfriendly, especially if the user is new here.
Questions shouldn't drag on as if they were a call to support, but if the question is framed correctly for the site it shouldn't immediately warrant a "go hire someone noob!" response.
I often feel bad for someone that shows up here saying "I inherited" or "I'm not an expert in this matter", etc. when they write a well thought out question. There are times when I have to ask a Linux question here and wouldn't want the Linux folks to simply assume I can't be prodded in the right direction because I'm used to Windows.