Lol there are almost always people high on psychedelics at deep creek. Much worse are the people who get extremely drunk, especially on alcohol coming from a glass bottle. I went this weekend and there were a lot of very large families(10+) which were fine but a whole family would overtake the pools and they were wearing shorts and tshirts in the springs.
Go on a weekday if you can, when its cloudy is best to avoid getting roasted by the sun, its no longer possible to shade under the rocks. Also PCT season has begun, there were about 6 thru hikers there on Sunday, most just stopped for a soak or to get water and kept on hiking.