Healing potions are way too dangerous to be such a publicly available product. If you even slightly overestimate an injury, the lasting side effects of a healing potion will be disastrous. Everything from rapid cancerous tumor growth to extreme aging can happen. A thing such as a magic cure all medicine should not be so readily available.
Just splashing a small amount of a weak health potion on an unsuspecting victim and you would absolutely ruin their life with extreme consequences.