I'm guessing here, but one advantage of the white glove, with the three lines to indicate that it is a glove, is that it doesn't prefer one skin color over another. This way, users of all types of skin colors wouldn't be immediately off put by, say, a caucasian ungloved hand.
Also, in the early 90s, the computer companies had to make home computing easy - that is, something a complete novice would not be afraid of spending $5000 on. Using a gloved hand was another way of making it seem like a butler or assistant was doing the work for you. Kinda like how Ask Jeeves worked. Or At Ease - if you can even remember that far back, lol.