Home Masses are not permitted in general. All Masses are to be public celebrations, not by “invitation only”. Mass should always be celebrated in a church or chapel with a consecrated altar or at least a blessed one. Only under necessity should Mass be celebrated elsewhere.
I know of many Masses celebrated “elsewhere”, always for a very special occasion, and likely by permission of the local Bishop.
While some Masses were in other locations, there was actually a general announcement that went out, as well as e-mails, etc. for maybe a specific group affected. Thus, it was not “private”. Had anyone expressed interest in coming, or showed up at the door, they would not have been turned away.
Additionally, “invitation only”…well, most people don’t randomly attend funeral or wedding Masses. They are held at the Church, of course, but they seem to be more “invitational” than anything. I have an adoration hour at the time on Saturdays in which weddings are usually scheduled in the main sanctuary. Although it is “public” I would actually not feel comfortably in attending that Mass.
By custom, if not by law, it is “invitation only”. Does that make it illicit? I don’t think it does.
I don’t really think home Masses are an abuse…the priests I know who have performed them have done so very reverently and have taken great pains to educate those who attended, and those people actually walked away with a far greater understanding of each movement of the Mass. None of them would want this to be done regularly, but saw this as a special glimpse, a special gift.
But I can see how this can be abused and why the law is needed and why it must be regulated.