It's possible that more people don't give that answer because it's too much like all those beauty queens who say they want world peace. It sounds hollow and trite to say it. Let's face it: we would rather want something that betters ourselves than be unselfish and ask for something that betters other people.
I sure as heck don't want the ability to heal other people because I don't want that kind of responsibility. People weren't made to physically live forever and there's a good reason for that: we'd go absolutely, positively insane after the first 100 years or so. Death would be something we'd wish for and we'd eventually wind up cursing (or crucifying) the person responsible for our endless misery.
Not to mention the fact that you'd get absolutely no peace whatsoever if you could magically heal someone. The world would be beating down your door and you'd continually be using your power to "do good" and you wouldn't have time for yourself or your family. At least, that's how it would be until the medical industry finally located you and put a bullet in your head because you were cutting into their profit margin.
Yep. I definitely spend way too much time thinking about these kinds of things.