I know this is old, but let me, as a Serb give some context.

I for one want a tolerant Serbia, yet it's also true that religion plays a big part in the public life here. Serbs are historically orthodox and it's part of Serbian identity.

For reasons beyond my understanding, most people here believe themselves to be the victim of the west. They see #EuroPride2022 as an invasion of their "traditional" culture. While it's obviously wrong, it's not unexpected they'd do this.