This hasn't been addressed in awhile but I too vote to enable PMs. We should have the freedom to decide whether or not PMs are something we want to utilize. I likely wouldn't use it extremely often, but it would be nice to have it as an option. :)
But how long has this site been up? Since 2003? And in all that time, PMs have never been enabled? Seems unlikely that they'd change that now, after all this time.