It would be the same to have blocked US people because Bush started an invasion that would cause hundreds of thousands to die. And I think that would be valid, certainly morally if not strategically.
Completely understandable, from my perspective. US citizens have a lot to answer for, just like Russian citizens, and should be held to account for their leadership choices.
They won't be, though, even if we assume they should be. "Holding Russian people to account", on the other hand, is emotionally easy and relatively consequence-free.