From what we've seen in Trek, Vulcans were a spacefaring people long before Humans were. They're an important part of the Federation. So how is it that the destruction of their homeworld reduces their numbers so drastically? They're obviously not isolationists, they should've been spread throughout the Quadrant on ships, on colonies, on other planets, etc. I get that they were upping the tragedy factor, but the destruction of the planet Vulcan was enough of a shock itself, they didn't need to make it so there's only a tiny amount of Vulcans left.
Spock would still have lost his mother and gone through the same emotional arc whether there was 10,000 Vulcans left or 10 billion.
Spock would still have lost his mother and gone through the same emotional arc whether there was 10,000 Vulcans left or 10 billion.