Other countries are similarly sanctioned, and hundreds of maintainers from those sanctions are still there. So the sanctions thing is absolutely just an excuse.
What Linus just did to Russians is scaring a lot of people right now, who are probably wondering if they should keep working in association with a project which has just demonstrated its unreliability.
Democratic socialists or social democrats? (Yes, there is a huge difference), because demsocs are just a type of communist (whereas socdems are capitalists / liberals)