Actually, lower numbers mean better performance. To understand why, you have to know what wing loading is.
Wing loading is how much weight is supported by each square foot of wing area. Here's a simple way to simulate it :
1) Take 2 bathroom scales and set them a few feet apart
2) Place a board on them so that it is laying across them evenly. I'll use a 6' 1X12 for simplicity
3) Put some weight on top of the board, right in the center. How about a few bricks, again for simplicity
Now, read the scales and add up the total. If this was an airplane, that would be your total load. At this point, you need to compute your wing area(6' X 1'=6 square feet). Lets say your 1X12 and bricks total weight is 18 pounds. By dividing the weight by the square footage (18/6), you would get your wing loading figure, in this case 3 pounds per square foot.
Now that you know what wing loading is, how does it affect an airplane? The higher the wing load, the harder it is for the wing to lift it. By adding bricks to the example above, the load gets heavier, till eventually the board breaks. A wing will do the same thing. By pulling too tight of loop, the wing won't be able to handle the stress, resulting in a wing failure. There fore, a lighter plane will be able to handle more stress on the wings due to lower loading. Hope this helps