As a slightly related aside, it's Lucien GREAVES, not Graves, and, yes, it is a stage name. No idea if he had it legally changed to that or not. He's quite an intelligent and sensible speaker and writer.
For the record, while I think I disagree with Thermal's ultimate conclusion(s), I tend to agree with the thinking that got him there, i.e., I agree that while legally TST is a religion, rationally I don't think it is; and while TST had every right to insist on putting the display in Chicago, it isn't put there for the same reasons as the others and is a small poke-in-the-eye as opposed to a festival celebration or demonstration.
Where I differ is in concluding that either of those characterizations means either that the display is a tactical mistake or that its different purpose makes it inappropriate.