Lots, structures, and uses of land and structures which were existing and lawful before this bylaw was passed or amended, but which are prohibited, regulated, or restricted under the terms of this bylaw, may continue under the conditions outlined hereinafter in this article. This bylaw is intended to permit these nonconformities to continue, but not to encourage their survival. Such users are declared by this bylaw to be incompatible with permitted uses in the districts involved.