why does linder claim to want them not to live there?

Lindner claims that negro families are happier living in their own communities. That people of like race living as neighbors makes for happier communities.

I want you to believe me when I tell you that race prejudice simply doesn't enter into it. It is a matter of the people of Clybourne Park believing, rightly or wrongly, as I say, that for the happiness of all concerned that our Negro families are happier when they live in their own communities.