[FreeKill]

I think the "taboo" in this case is the same way some people feel about sites like rentacoder or guru where the programmer (in this case designer) has to work their tail off trying to land a paying job where as the client pays next to nothing comparative to how much spec work they are getting done for free.

Although in my opinion, no one is forcing either to work with those sites and in fact a lot of top designers stay away for just that reason. It devalues what they think their time is worth...

So, some people who work in a similar contracting style field feel it's taboo to hire someone in another field using a process you think is exploitative in your own field.