I'm not above killing my players, in fact I think it's part of a healthy game and helps bring focus back. Nothing gets a player's attention like the words, "You're dead." Disbelief always follows and it takes me a couple times of explaining what just happened before the reality sinks in. Yet, in my games, I seek to provide entertainment above all else. There's a time for killing, and there's a time for story. Generally, story takes charge and the players get a few miracles tossed their way.
Just like with writing, I think running a table-top game is entertainment. As the DM/GM, it's my job to make things fun. If I had players dropping like flies, it wouldn't be fun for anyone and I'd lose people wanting to play. So I see no problem fudging the dice-roll to make things move the way I want to.
Yet on the flip-side, I have never, nor will I ever fudge or lie about a roll that would cause a player to die. It all goes back to the entertainment and fun aspect. Oh there's been plenty of times that I've sat in disbelief that nobody died, but it just adds to the fun.
Remember, if it isn't fun, do something else. This applies to almost everything.