We have an amateur in the area who likes camp out on the six meter calling frequency and have his voice keyer automatically call CQ for a few hours some evenings. It's logical to do such a thing as no one will know the band is open unless someone is transmitting and someone receives the transmissions. But it's terribly annoying to listen to and I find myself getting frustrated when people do this. I know others feel the same way as well. Despite being a calling frequency it's impolite to use it for calling for long periods of time.
Perhaps what we should really have are multiple calling frequencies based on areas such as grid square fields, the first two characters of the Maidenhead Locator System (i.e. "FN", "EM", "CN", etc.). You could camp out on the frequency for your grid square field and call CQ all you like, but if you just wanted to listen for an opening, you could leave your receiver on one of the other grid square field frequencies and not have to worry about a local station clogging the frequency for long periods of time.