Maybe grow some balls as a designer and say "You can't beat this game if you refuse to level up and talk to anybody"
Lower the rate of stimpacks in randomized loot to a more reasonable level, handplace the majority of found stimpacks in the world, and have a steady (yet expensive) supply of them come into shops in case the player does run out. Balance the gameplay so that the player doesn't NEED them if they're playing carefully.
Adding weight to them DOES add something. It means the player can't hoarde a million healing items and become invincible. It means that players that choose to have extra strength get an added benefit. But yeah, god forbid someone who gimps their character in a specific way gets annoyed by the consequences of their decision.