At Appconomy, we used See[Mike]Code to do technical phone screens. One or two developers would jump on a call and have the candidate write a couple of simple functions in the programming language of their choice. These were bozo filter kinds of coding questions, nothing complicated. Ideally, the process would take 10-15 minutes, including the initial pleasantries. We just wanted to make sure the candidate actually writes code before we would bring them in. We did this as a last screen before bringing someone in for an onsite interview -- after screening resumes and having our HR Director do her phone screen.
One afternoon, our HR Director stopped me and a colleague (coincidentally his name is Mike) in the hall. She said somewhat meekly, "I just had a candidate decline to do your coding test. He said, 'I cannot condone that kind of interview practice.'". Mike and I looked at one another quizzically and then he turned back to her. "Perfect, it's working better than we ever imagined."
I don't know what this person's real objection was, but if you are interviewing for a programming job, there are no valid reasons to object to writing a small amount of code as a part of the process. With few exceptions (e.g., your name is DHH), there is no reason to object to a bozo-filter. Just remember, if you're good enough to get hired (and if you're objecting, you must think you're a lock to be hired), you will eventually be the one who's doing interviews when you could be coding. When that day comes, you will appreciate having a good, fast filter in place.