Absolutely, James. I used to read for our university literary magazine as a grad student, and the slush piles were enormous (because in just a few short years, this magazine has acquired a great reputation). In the beginning, I only had to read manuscripts and decide whether or not to pass them on to the fictio editor. But then, second year, they decided it would cut down on response time to saddle us readers with the actual responsibility of deciding to reject the manuscript or pass it on, and to send the actual rejection letters to the authors. We were provided with the form rejection slips and given specific instructions on how to fill them out: The words "Sorry to say no," with our initials (never full names) signed beneath.
But that seemed so cold to me, and because I envisioned myself as this great, caring person who understood all too well what writers go through, I wanted to take time out to send a detailed handwritten response to each rejection. And I did do this a few times, especially with some near-misses, and got really nice letters from those writers in return. However, the downside of this practice is that after awhile you realize it's just downright impractical, not to mention unrealistic. When you have over a hundred manuscripts to plow through, not to mention your own work and responsibilities, you learn to cut corners--whether you like it or not, and no matter how much it goes against the grain of your personal philosophy.
And when I realized it was taking me over six hours a day just to get through five or six manuscripts--many of them god-awful and deserving of nothing more than a form rejection, I became callused pretty quick, and not adverse at all to writing that simple "Sorry to say no." But I can't say I ever really got the hang of doing so completely without guilt, so I'd probably never be much of an editor.