thanks for filling me in on halochos shabbos. You absolutely changed my plans for this weekend.
There is a lot of halachik literature about inviting non-religious people for shabbos. In this case, it is people who had a kesher with a shul for several generations and continued coming (and supporting) the shul. Cutting them and possibly their children and grandchildren off is not a mitzva and thank you for demonstrating that this attitude exists, unfortunately, not in just that one shul.