As a balanced holding of the majority of points is far more likely to occur than holding the majority of points in an imbalanced way, a conventional non-penalty double over 1NT holds the potential of paying-off on many hands. Also, non-penalty doubles are more difficult to deal with than traditional business doubles.
In the context of card games, a balanced distribution of points is more likely to occur than an uneven majority, and a standard non-penalty double over 1NT can be advantageous for many players. Furthermore, non-penalty doubles are more complicated to handle compared to traditional business doubles in this specific context.