Hi,
If all the products in the cart have no weight and without the "Force shipping regardless of weight" activated, the shipping is not required on the checkout. Thus, the shipping method selection interface and the shipping address interface won't display and the shipping methods won't even be loaded.
Also, HikaShop can't base itself on the weight restriction settings of your shipping methods. Suppose you sell both virtual goods and shippable goods with a fee. You want the shipping methods to display only for the shippable goods and none for the virtual goods. But if you where to use the "minimum weight" setting for that, you would end up with a "no shipping method found" error during the checkout as shipping would still be required but no shipping method would be found matching the situation for virtual goods.