Mr. Tobias, thank you for your informative post.
Yes, that specific day of the year seems to be one of the favorites among the neopagan wannabies. Based on my personal experience, people who organize and attend such events belong to three groups:
1) true believers, who actually believe all that BS (a very small and often quiet group);
2) smart politicians, who see participating in such events as going with the flow (they are the ones who are the most vocal and visible);
2) tourists, who just want to see a curious attraction (most of the spectators).
June solstice celebration in an obscure region of godless South America.