Depends on the age too. If it's a little kid I can see that being more of a valid argument. If it's a really young kid I'd probably start them on a nylon string for several reasons. The one the you mentioned about the pain, the fact that it is an acoustic guitar, so you don't need an amp or electricity to play, which also gives you portability and the ability to practice anywhere.

You also would have to replace strings less often. A beginner usually doesn't worry about or even know that when they should be changing strigns. Nylon strings can last a hell of a long time, while steel strings can get dirty and get a rough "rusty" texture, which leads to even more discomfort (and money for strings).

If it's an older kid, young adult, or an actual adult I'd say it doesn't matter. You can afford to "worry" about all the other stuff at that point. And if it's too much then they don't deserve to be playing guitar :p