Should society dispose of individuals that they know will contribute more negatively than positively?

Absolutely not. Society cannot possibly know if someone will contribute negatively or positively. Every single human being on this planet will make mistakes at some point in their life so if you got rid of everyone who would possibly cause a bad effect in the world then everyone would be dead. negativity is relative, some ppl think that cheating is worse than killing, while with other ppl it's the other way around so who is right? Its the same with positiveness. Some ppl believe that community service is more important than raising your kids to be good young men and women, while others find the reverse is true. If you base your opinions about somebody's worth on one person or on "society" you will almost certainly go wrong because nobody is perfect except for God and he judges us on the last day.