I think Hostel was more of a reflection of the time. A lot of "torture porn" movies came out during the War on Terror and War in Iraq while the Bush administration admitted to using torture, there was the abuse at Abu Ghraib, and there was rampant xenophobia in the US because of 9/11. Instead of saying "foreigners are bad" it was just reflecting the fears people had. And weren't white Europeans the villains in Hostel?

The Ruins is about the killer plants and the white tourists who go where they aren't supposed to. Once the tourists went to the top of the pyramid and got infected the indigenous people killed them to keep them from leaving and spreading the plant.

The Wicker Man to me seemed like British Christian conservativism struggling against a community that rejected the christian-conservative values. Midsommar didn't really seem reactionary to me either, but I haven't seen it since it was in theaters.

I love horror, and there is a lot of reactionary elements, but there's also a lot of subversiveness within the genre. just because it seems to be reactionary on the surface doesnt mean that it is.

Edit: sorry if I sound mean or it doens't make sense I'm still waking up lol