It’s for the same reason they want a war with Russia.
Ironically it’s the Putinists and Russian trolls on these boards that peddle pro-Iran, pro-Syria nonsense along with their anti-Saudi points. (Usually as a way to mask their latent anti-Israel and anti-Semitic sentiments.)
And those who attempt to pit Shiites and Sunnis against the other as if there is a real difference.
There isn’t.