Resigning from schengen contract would also mean that swiss people couldn't travel freely across the Europe. That would be way bigger problem than the potential handful of Russian tourists around there as it's not that uncommon to go across country borders on your grocery shopping. I very much doubt that Swizerland would shoot itself on both feet, no matter how strong ties someone around there might have to Russia.

Oh I did not know that.

Though I have no doubt an optional referendum would happen (it just needs 50k signatures). Plus the SVP, while the biggest party, is only like 30% of government, so it's doubtful they could push this through by themselves.