If we put on our blinders and ignore the larger issue, asking an artist for free stuff is rather condescending. As Mueller says, why should magazines, advertisers, websites or corporations expect or ask for free work? (Let's not pretend it's anything other than this) If the artist didn't already put it on a Creative Commens license or similar (or has indicated that he is willing to give non-commercial licenses to people who ask), then flat out asking artists for free stuff to further your own company is tantamount to asking for a free lunch.
In this narrow sense, Tristan's "giving things away for free makes me and people all over the world happy" post is not an argument against that either. It's just a feel-good argument for using a CC-type license in the first place, which was never the issue.
It might just be a difference in cultures, but in my experience if you, for example, ask a sys-admin for Linux help, they are more than happy to spend time on it. There is no stigma about asking for this sort of help even though you're basically asking a professional to work for free (at least in the Linux communities I'm familiar with). I've seen people spend hours helping others debug some issues.
Also, most programmers I know (admittedly all are at least open source enthusiasts) are all more than happy to provide you with little scripts. They are not only willing to allow you to use their code, but also usually happy to support that code for free to some extent (people are usually happy to help you get it set up, at the very least). I've mostly seen this on smaller programs and scripts, but those are not much different in scope from a single photograph.
On the latter point, sometimes people are downright ecstatic to do so; if someone wrote up a little piece of software and stuck it online, and then never heard from anyone, they're often really pleased if you write in with a question, because it means someone actually is using the software for something.
There is just one thing that I would point out: the sys admins and programmers are most likely already making money through their employment. In the case of a photographer, (s)he is selling the photographs for a living. I'm sure that if you ask a professional photographer for help in taking better photographs, he will gladly help you.
In this narrow sense, Tristan's "giving things away for free makes me and people all over the world happy" post is not an argument against that either. It's just a feel-good argument for using a CC-type license in the first place, which was never the issue.