Why do people keep trying to feed their plants people vitamins?

Did you even read what slowthestone wrote? It's totally the wrong concentrations. You can kill your plants, stunt their growth, etc.

But go ahead keep asking until someone [probably a newb with a post count of like 3] gives you the answer you want, which is, "yeah, they work awesome, my sister's roommate's boyfriend gives his plants one pill at every watering and gets buds the size of your arm they are fully mature and ripe for harvest in only 2 weeks from seed..."