First off: Yes it’s intentional that there is some sort of penalty for going over the weight limit. However ideally we want players to still be able to move several screens before being forced to do something about stamina (either by eating, resting or using refresh potions). But it goes without saying that someone with 10 dexterity/stamina will notice the effects sooner than someone with 100+ dexterity/stamina.
p.s. We will be reducing the drain even further upon next reboot.