Matthew,
It's all over the board. Some clients do, and many architects comply willingly. I might, if it was a truly great project, but usually those kinds of clients don't ask for the freebies, its the ones just scraping by.
What I try to do is negotiate a break even type routing plan, usually sub $5K and then credit that to any final fee. I tell them that if I did 10 of these free to get one job, I would have to add $50K to my fee, so they end up paying somewhere in the long run. Sometimes they buy it.
The realities of the world really never change. The types of clients who would ask for free work won't stop once you get the project commission. But, so many architects struggle to get work, that it happens. And, most of us aren't very profitable as a result!