Locking advocates are wrong, if there is such a thing as one who advocates for that. Every team I've met using the old-fashioned locking style system has complained about it, and looked longingly at the people using other methods. I worked on a project for one place that were forced to use a locking system and opted to use NO CONTROL at all (so I set up a secret SVN branch, even though I much prefer Bzr or Git).
So, I suspect that the only "locking advocates" are employees of a locking system's marketing department.