If you live in England, you are probably not aware of just how much Hogmanay is celebrated in Scotland - though maybe you used to watch the TV broadcasts (mostly very tame, though I remember one where the organisers must have been less than stone cold sober, and one performer was clearly heard muttering about their ineficiency).
The last time the street party was held in-person, in 2019, it was attended by 75,000 people. Some people get extremely cross if their fun is restricted. I don't think it would have been very funny if this idiot had succeeded in setting up a mob of 1,000 drunken nitwits outside the FM's private house at Hogmanay. Some brave soul would certainly have flung a brick through the window or something similar. A riot would have ensued.