There are two meals under discussion in I Corinthians 11: common meals, which should be taken at home, and the Lord's Supper, which is to be taken by Christians assembled together. Were the Corinthians having a potluck instead of partaking of the Lord’s Supper? covers the distinction between the two types of meals. I Corinthians 11:33 is talking about the Lord's Supper because it was to be taken when they come together (I Corinthians 11:20-22). It is contrasted with a common meal in the next verse, which was to be eaten at home (I Corinthians 11:34).
The idea that because space was being used for things the Lord did not authorize, that it should continue does not make sense. It is like the couple who argue that since they have already moved in together before marriage, they might as well stay there. Changing a hall into additional classroom space is not that difficult of a construction job. It does not require tearing down everything.
The fact that the church allows groups to use the building purchased with the Lord's money -- groups that have nothing to do with spreading the gospel -- only shows how the group considers the Lord's money to be their own. That money was not applied for a holy purpose. It was common, worldly matters. See: Holy is His Name and Regarding God as Holy.
Perhaps another article will help clarify the issues for you. See: Kitchens and Fellowship Halls: What Was the Issue?