A protected question prevents answers by very new users. Questions should be protected when they are garnering lots of views and newbies are adding "me too!", "thanks!" and possibly even spam non-answers — incidentally, which seems to happen most often when a question is blasted out to large numbers of people who do not understand Stack Exchange.
But English SE has "protected" almost 1,000 questions. That's over 5%, almost twice the #2 site, and 20 times more than most of the network! I'm not sure why most of those questions needed protecting at all.
Preemptively Blocking Users?
The protect-question tool is extremely useful when "we've seen enough poor answers." But when you start to proactively protect questions just in case, you are blocking the most basic functionality of the site for a large number of users. That's not how Stack Exchange is supposed to work, and that's not the purpose for which the tool was designed.
Having said that, I don't run this site. You do. So I'm asking about the policies behind the use of this tool, and if perhaps a little introspection and adjustment is needed.