Every time that I read this it means more to me:

1 Cor 12:22-24
22 On the contrary, those parts of the body that seem to be weaker are indispensable, 23 and the parts that we think are less honorable we treat with special honor. And the parts that are unpresentable are treated with special modesty, 24 while our presentable parts need no special treatment. But God has combined the members of the body and has given greater honor to the parts that lacked it,
NIV

This is talking about parts of the body of Christ and it clearly says that God has given greater honor to the parts that lacked it. And in verse 22 God says On the contrary, those parts of the body that seem to be weaker are indispensable.

So why does Society dispose of the disabled?

Because Society is out to please itself and not God.