I try my best to break people of that awful habit. I also find that I'm usually happy enough dealing only with people who can manage to open a pdf (or any other non-proprietary format).
I had a friend tell me my CV should be in PDF and locked down to prevent recruiters and others from changing it to something other than the original. I know recruiters are fond of changing things up without informing you.
Can you elaborate? Why would they want to change your CV?