I see the issue. I guess we need to live with this because if I did enable load page on the click, there is no way for the user to navigate to the submenu item since every time you click on the parent menu item, you end up loading the page. Hope you get it.
In desktop world, we have two ways to navigate – hover and click and hence it is ok to just open the page when you click on the URL since hover will enable you to navigate still to the submenu item. In the mobile world, there is only touch(=click) action that we use to arrive at the submenu item and hence we need to disable navigation on touch of the parent menu item.
The way I have been handling this is by having the page linked to by the parent menu item listed also as submenu item so that users do not miss out on the same. When the hover gets enabled and submenu is shown, users often do not click on the item itself and hence you can lose some traffic on that page.