We're facing the same issue - and same objections. Once a program is popular enough (eg: Asterisk, nagios) it is considered appropriate for installation questions, how to questions, etc. But until a program reaches that level of popularity it is considered inappropriate. Offering another opinion here: if this brings new users, good questions, and good answers to SF, should that be ok?
I agree that some questions (like how do I copy a file) are better suited to sites targetting new users (and don't contribute much to the value of SF). But those questions get downvoted anyways.
The upside is that SF will draw in experts from different vendors provide right-on technical answers. The downside is it will draw in low-value (i.e. stupid) questions as well. I'm not saying this is clear cut either way - but certainly an argument for both views.
We want to support SF as best we can (in terms of relevant questions AND answers). On our part we'll encourage customers to use the most appropriate forums (eg: ubuntuforums.org for simple questions unique to ubuntu), and only post to SF if question are technical, apply to a broad audience, and fit with SF's mandate. We'll also make clear that "technical support" is available directly from our company.